JP2005302455A - Fuel cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To operate a solid polymer fuel cell stably by discharging water in a gas passage groove. <P>SOLUTION: An anode gas passage opposed to an anode 72 is formed in an anode-side plate 20. A cathode gas passage opposed to a cathode 74 is formed in a cathode-side plate 80. A cell is mainly composed by sandwiching an MEA 70 between the anode-side plate 20 and the cathode-side plate 80. Gas discharging manifold holes 42, 46 penetrating a layered body 10A are formed in the anode-side plate 20 and the cathode-side plate 80. A water-absorbing member 60A is provided in a downstream part of at least one of the anode gas passage and the cathode gas passage. The water-absorbing member 60A has an extending portion extending to the inside of each of the gas discharging manifold holes 42, 46. This allows water to be discharged to manifolds without staying in an outlet header 48. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell stack. More specifically, the present invention relates to a fuel cell stack that suppresses blockage of gas flow paths.

  In general, in a polymer electrolyte fuel cell stack, a membrane electrode assembly (hereinafter referred to as “MEA”) is configured by joining an anode to one surface of a solid polymer electrolyte membrane and a cathode to the other surface, A cell is configured by sandwiching the MEA between an anode side plate provided with a fuel flow path facing the anode of the MEA and a cathode side plate provided with an oxidant flow path facing the cathode of the MEA. A fuel cell is configured by stacking a plurality of cells having such a structure to form a laminate, and attaching and tightening end plates to both ends of the laminate.

  In the polymer electrolyte fuel cell, a fuel gas such as a reformed gas is circulated through the anode side plate, and an oxidant gas such as air is circulated through the cathode side plate to cause an electrochemical reaction through the electrolyte membrane. To generate DC power.

  In the polymer electrolyte fuel cell, it is necessary to moisturize the electrolyte membrane in order to ensure the ionic conductivity of the solid polymer electrolyte membrane during operation. Therefore, there are many conventional methods of supplying fuel gas and air after humidification It is used. In addition, by distributing fuel gas and liquid water to the anode side gas flow path and distributing them together, the fuel gas can be efficiently supplied to the anode and the electrolyte membrane can be efficiently moisturized, and the battery can be cooled. Polymer fuel cells have also been developed.

  In order to obtain excellent battery characteristics in a fuel cell, it is necessary to distribute fuel gas and oxidant gas throughout the anode or cathode. For this purpose, it is necessary to prevent the gas flow grooves on the anode side and the cathode side from being blocked with water to obstruct the flow of the fuel gas and the oxidant gas.

For this reason, conventionally, it has been known that the fuel gas flow channel groove is directed vertically and the fuel gas is circulated downward so that water is easily discharged, and a water absorbing material is disposed at the gas flow channel groove outlet. (For example, Patent Document 1). According to this, since the water generated in the fuel gas flow path is discharged to the manifold through the water absorbing material, the water can be quickly removed from the vicinity of the fuel gas flow path groove outlet. Less blockage.
JP 2001-176522 A

  However, since the outlet header provided at the outlet of the fuel gas channel groove or the oxidant gas channel groove is usually very shallow, water tends to stay in the outlet header. The amount of the staying water varies depending on the cell, and in a cell having a lot of staying water, the supply amount of the fuel gas and the oxidant gas to the cell is lowered, resulting in a voltage drop.

  The present invention has been made in view of these problems, and an object of the present invention is to quickly discharge water generated in the gas flow channel into the manifold so that the fuel cell can be stably operated. Is to provide.

  An aspect of the present invention includes a membrane electrode assembly in which an anode is disposed on one surface of an electrolyte membrane and a cathode is disposed on the other surface, an anode side plate in which an anode gas flow path facing the anode is formed, A gas exhaust manifold that includes a stacked body in which a plurality of cells composed of a cathode side plate formed with a cathode gas flow path facing the cathode is stacked, and penetrates the stacked body through the anode side plate and the cathode side plate The present invention relates to a fuel cell stack in which is formed. The cell further includes a water absorbing member disposed downstream of at least one of the anode gas channel and the cathode gas channel, and the water absorbing member has an extending portion extending into the gas discharge manifold.

  According to this aspect, since the water absorbed by the water absorbing member at the lower end of the anode gas channel or the cathode gas channel is quickly drained to the gas discharge manifold by the water absorbing member, the outlet header of the anode side plate or the cathode side plate In this case, water does not stay in the gas flow path, so that blockage of the gas flow path due to water clogging is suppressed. Therefore, the variation in the voltage drop of each cell is reduced, and the fuel cell can be stably operated. In order to effectively discharge water from the gas channel, the downstream side of the gas channel is preferably on the lower side in the vertical direction of the plate.

  Another aspect of the present invention is a membrane electrode assembly in which an anode is disposed on one surface of an electrolyte membrane and a cathode is disposed on the other surface, an anode side plate having an anode gas flow path facing the anode, And a cathode side plate in which a cathode gas flow path facing the cathode is formed, and a laminated body in which a plurality of cells are laminated, and gas discharge through the anode body plate and the cathode side plate through the laminated body The present invention relates to a fuel cell stack in which a manifold is formed. The cell covers at least one of the anode gas channel or the cathode gas channel so as to face the channel bottom, and a tunnel channel forming plate provided with an opening corresponding to each gas channel; A water absorbing member disposed on the tunnel flow path forming plate and covering the opening.

  According to this aspect, the water traveling on the gas channel groove side of the tunnel channel forming plate enters the opening opened in the plate and is absorbed by the water absorbing member placed on the upper surface of the opening. Blockage due to water clogging at the lower end of the channel groove is suppressed. In addition, an opening part can take various shapes, for example, includes a through-hole and a slit. The water absorbing member may have an extending portion that extends into the gas discharge manifold. Thereby, the water absorbed from the opening can be guided to the gas discharge manifold. In addition, even if a water absorbing member is a single member, it may be comprised by the lamination | stacking of two or more members.

  The extension part of the water absorption member of each cell may be mutually connected in the said gas exhaust manifold. According to this, since water discharged from each cell is successively transmitted through the water absorbing member in the gas discharge manifold, it is possible to discharge water to the outside of the fuel cell stack. In addition, the term “connected to each other” includes a case where the extended portion is connected to a cell adjacent in one direction and a case where the extended portion is connected to cells on both sides.

  The extension portion is bent in the gas discharge manifold, and the fuel cell stack may be configured such that the bent portion contacts the extension portion of the water absorbing member of the adjacent cell. Or, the extension portion is bent in the gas discharge manifold, and further includes a connection water absorption member that extends in the stacking direction of the gas discharge manifold and contacts the extension portion of the water absorption member of each cell. May be. According to this, since water discharged from each cell is successively transmitted through the water absorbing member in the gas discharge manifold, it is possible to discharge water to the outside of the fuel cell stack. Note that “bending” includes both a case where the water absorbing member is bent and a case where the water absorbing member is bent smoothly. Further, “contact” includes both a case where the water absorbing members are simply in contact with each other and a case where they are overlapped.

  The water absorbing member may be formed in accordance with the shape of the gas flow path outlet portion of the anode side plate or the cathode side plate. For example, in the case of a fuel cell stack in which an outlet header is provided downstream of the anode gas passage of the anode side plate or the cathode gas passage of the cathode side plate, the shape of the outlet header and the shape of the water absorbing member are substantially the same. If the water absorbing member is arranged over the entire outlet header, water does not stay in the outlet header. In addition, in the case of a fuel cell stack provided with an anode side plate or a cathode side plate that is not provided with an outlet header and has a shape in which the anode gas channel or the cathode gas channel opens directly into the gas discharge manifold hole. A water absorbing member that protrudes from the lower end of the gas flow path into the gas discharge manifold hole may be provided in each gas flow path.

  A combination of the above-described elements as appropriate can also be included in the scope of the invention for which patent protection is sought by this patent application.

  According to the fuel cell stack of the present invention, since the blockage of the gas flow channel groove by water is suppressed, the polymer electrolyte fuel cell can be stably operated.

Embodiment 1 FIG.
The configuration of the polymer electrolyte fuel cell according to Embodiment 1 will be described with reference to FIGS. FIG. 1A is a plan view of the anode side plate 20, and FIG. 1B is a cross-sectional view taken along a line AA ′ in FIG. It is sectional drawing cut out.

  The MEA 70 is configured by disposing an anode 72 and a cathode 74 on a solid polymer electrolyte membrane 76. The anode side plate 20 is provided with a plurality of fuel gas flow channel grooves 22 facing the anode 72 of the MEA 70, and the oxidant gas flow channel groove 82 facing the cathode 74 of the MEA 70 on the cathode side plate 80. Is provided. Mainly, the MEA 70 is sandwiched between the anode side plate 20 and the cathode side plate 80 to constitute a unit cell, and a laminated body 10A is constituted by laminating a predetermined number of these cells. A pair of end plates (not shown) for fastening the laminated body are arranged at both ends of the laminated body 10A, thereby constituting a part of the polymer electrolyte fuel cell stack.

  A fuel gas supply manifold hole 32, a cooling water supply manifold hole 34, and an oxidant gas supply manifold hole 36 are opened in the upper part of the anode side plate 20. An inlet header 38 is provided below the fuel gas supply manifold hole 32 of the anode side plate 20, and a plurality of fuel gas flow channel grooves 22 extending downward in the vertical direction are provided from the inlet header 38. By arranging the anode side plate 20 in this way, the influence of water clogging can be reduced by the effect of gravity. The size of the fuel gas passage groove 22 is, for example, a width of 0.5 mm and a depth of 0.3 mm. The fuel gas channel groove 22 faces the anode 72 of the MEA 70. An outlet header 48 that is a space communicating with the plurality of fuel gas passage grooves 22 is provided below the fuel gas passage groove 22.

  A fuel gas discharge manifold hole 42, a cooling water discharge manifold hole 44, and an oxidant gas discharge manifold hole 46 are opened below the anode side plate 20. As can be seen from the cross-sectional view of FIG. 1B, the fuel gas supply manifold hole 32 communicates with the inlet header 38, and the fuel gas discharge manifold hole 42 communicates with the outlet header 48.

  A plate 30 for forming a tunnel flow path is disposed facing the inlet header 38 and the upper part of the fuel gas flow path groove 22. Similarly, a plate 40 for forming a tunnel channel is disposed facing the outlet header 48 and the lower part of the fuel gas channel groove 22.

  Similarly to the anode side plate 20, supply manifold holes 32, 34, and 36 and discharge manifold holes 42, 44, and 46 are formed in the cathode side plate 80. The cathode side plate 80 is provided with an inlet header (not shown) that communicates with the oxidant gas supply manifold hole 36 and an outlet header (not shown) that communicates with the oxidant gas discharge manifold hole 46. Between the inlet header and the outlet header, an oxidant gas channel groove 82 (see FIG. 1B) such as the fuel gas channel groove 22 is provided, and this oxidant gas channel groove 82 is the cathode of the MEA 70. 74 is opposed.

  Further, a concave portion is formed on the back side of each of the anode side plate 20 and the cathode side plate 80, that is, the surface opposite to the surface facing the MEA 70. By superposing the back surfaces of the anode side plate 20 and the cathode side plate 80, the recesses are combined to form the cooling water flow path 58.

  As shown in FIG. 1B, the anode side plate 20 and the cathode side plate 80 are laminated, so that the supply manifold holes 32, 34, 36 and the discharge manifold holes 42, 44, 46 are connected to each other. A manifold communicating in the stacking direction of 10A is formed. A gasket 54 is sandwiched between the anode side plate 20 and the cathode side plate 80, thereby sealing the four sides of the MEA 70 and the manifold.

  A water absorbing member 60 </ b> A is disposed in contact with the terminal portion of the fuel gas channel groove 22 in order to quickly absorb and drain the water generated in the fuel gas channel groove 22. The water absorbing member 60A is shown with dots in FIGS. 1 (a) and 1 (b). As shown in FIG. 1B, the water absorbing member 60 </ b> A is fitted in a recess formed in the anode side plate 20 and spreads over almost the entire surface of the outlet header 48.

  In this embodiment, the water absorption member 60A protrudes to the fuel gas discharge manifold hole 42, and the manifold side tip of the water absorption member 60A is positioned higher than the level of the water staying in the manifold.

  The water absorbing member 60A is made of, for example, a material such as polyester, polyethylene terephthalate, rayon, rayon / polyethylene terephthalate, nylon / polyethylene terephthalate, rayon / polyclar, a woven fabric, a nonwoven fabric or felt, or porous carbon. The porous material can be used.

  Next, the flow of the reactive gas in the stacked body 10A will be described.

  The fuel gas is distributed and supplied to each cell through a fuel gas supply manifold hole 32 communicating with the stacking direction of the stacked body 10A. The fuel gas used is one that is bubbled in water and humidified. The fuel gas supplied to each cell passes through the inlet header 38 and flows through the fuel gas flow channel 22 to supply hydrogen to the anode and humidify the solid polymer electrolyte membrane. As the fuel gas, hydrogen gas or natural gas mainly composed of hydrogen, reformed gas such as propane, butane, and methanol can be used.

  On the other hand, an oxidant gas such as air is distributed and supplied to each cell through an oxidant gas supply manifold hole 36 communicating in the stacking direction of the stacked body 10A. The oxidant gas supplied to each cell passes through the inlet header and flows through the oxidant gas flow channel 82 to supply oxygen to the cathode.

  In each cell in which the fuel gas and the oxidant gas flow, electric power is generated by an electrochemical reaction through the solid polymer electrolyte membrane 76. Unreacted fuel gas discharged from each cell merges at the outlet header 48 and is discharged to the outside of the stacked body 10A through the fuel gas discharge manifold hole 42 communicating in the stacking direction of the stacked body 10A. The discharged unreacted fuel gas is generally introduced into a reformer burner of a fuel reformer (not shown) and burned.

  Further, the unreacted oxidant gas discharged from each cell after power generation merges at the outlet header, and is discharged to the outside of the stacked body 10A through the oxidant gas discharge manifold hole 46 communicating in the stacking direction of the stacked body 10A. Is done.

  The cooling water is distributed and supplied to the respective cooling water flow paths 58 through the cooling water supply manifold holes 34 communicating in the stacking direction of the stacked body 10A. The cooling water flowing through each cooling water channel 58 cools each cell and holds it at an appropriate operating temperature (for example, about 70 to 80 [° C.]). The cooling water is discharged to the outside of the stacked body 10A through the cooling water discharge manifold hole 44 that communicates in the stacking direction of the stacked body 10A.

  The water generated in the fuel gas channel groove 22 of the anode side plate 20 is discharged to the outlet header 48. Since the outlet header 48 is inclined toward the fuel gas discharge manifold hole 42, the water is discharged into the fuel gas discharge manifold hole 42. However, since a mixture of fuel gas and water flows in a narrow fuel gas channel groove, water stays in the middle of the channel groove, which causes water blockage in the channel and hinders gas flow. . Further, since the outlet header 48 is very shallow, the water discharged to the outlet header 48 tends to stay in the outlet header. The amount of the staying water varies depending on the cell, and in the cell having a lot of staying water, the supply of the fuel gas to the anode becomes non-uniform, resulting in a voltage drop.

  In this embodiment, the water staying in the most downstream portion of the fuel gas flow channel groove 22 is absorbed by the water absorption member embedded in the wall surface on one side of the fuel gas flow channel groove 22, and the water absorption member is the outlet header 48. Since it is formed in accordance with the shape, water does not stay in accordance with the water gradient in the water absorbing member and is quickly discharged into the fuel gas discharge manifold hole 42.

  According to the embodiment described above, the following effects can be obtained. That is, if a water absorbing member is provided in the outlet header so as to be in contact with the lower end of the fuel gas supply groove, and the end of the water absorbing member is at a position lower than the lowermost end of the outlet header, the accumulated water in the outlet header is absorbed by the water absorbing member. The material is sucked and discharged into the fuel gas discharge manifold. This can reduce clogging of the gas flow path caused by moisture for humidifying the electrolyte membrane, and can quickly remove the accumulated water in the outlet header. In addition, since the stagnant water in the outlet header is quickly removed, fuel gas passages are secured, and the flow of gas flowing through each fuel gas passage groove becomes uniform, improving battery characteristics. Can do. Moreover, since the time-dependent fall of generated voltage can be suppressed, a high voltage can be obtained even after long-time operation. Even if a water absorbing member is provided in the outlet header so as to leave a minute gap, for example, a gap of about 0.5 mm, between the lower end of the fuel gas supply groove and the water absorbing member, the same effect as described above can be obtained. it can.

Embodiment 2. FIG.
FIGS. 2A and 2B are diagrams illustrating the configuration of the polymer electrolyte fuel cell stack according to Embodiment 2. FIG. FIG. 2A is a plan view of the anode side plate 20, and FIG. 2B is a cross-sectional view of a part of the stacked body 10B of the polymer electrolyte fuel cell stack, taken along the line AA ′ in FIG. It is sectional drawing cut out. The second embodiment has the same configuration as that of the first embodiment except for the shape of the water absorbing member 60B. Therefore, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same member.

  FIG. 3 shows the shape of the water absorbing member 60B according to the second embodiment. As shown in the drawing, the water absorbing member 60 </ b> B has an extending portion 64 extending into the fuel gas discharge manifold hole 42 in addition to the trapezoidal portion 62. The extending portion 64 is bent before coming into contact with the bottom surface of the fuel gas discharge manifold hole 42, and the extending portion of the water absorbing member 60 </ b> B extending from the anode side plate 20 of the adjacent cell is ahead of the bent portion. 64 has a length sufficient to contact 64. Accordingly, as shown in the cross-sectional view of FIG. 2B, the water absorbing members 60B extending from the anode side plates 20 of the adjacent cells are successively brought into contact with each other, thereby connecting the water absorbing members in the stacking direction of the stacked body 10B. be able to.

  By adopting this configuration, moisture transferred from the outlet header 48 into the fuel gas discharge manifold hole 42 via the water absorbing member moves to the adjacent water absorbing member 60B one after another due to the water gradient of the water absorbing member 60B. The gas moves through the gas discharge manifold hole 42 and is quickly discharged out of the stacked body 10B.

Embodiment 3 FIG.
4 (a) and 4 (b) are diagrams illustrating the configuration of the polymer electrolyte fuel cell stack according to Embodiment 3. FIG. FIG. 4A is a plan view of the anode side plate 20, and FIG. 4B is a cross-sectional view of a part of the laminated body 10C of the polymer electrolyte fuel cell stack, taken along the line AA ′ of FIG. It is sectional drawing cut out. The third embodiment is common to the second embodiment in that the extending portion of the water absorbing member 60C extends into the fuel gas discharge manifold hole 42. However, the third embodiment is different from the second embodiment in that another connecting water absorbing member is provided in the fuel gas discharge manifold hole 42 in addition to the water absorbing member 60C. This difference will be described with reference to FIG.

  FIG. 5 shows the shape of a water absorbing member 60C according to the third embodiment. As shown in the drawing, the water absorbing member 60 </ b> C has an extending portion 66 extending into the fuel gas discharge manifold hole 42 in addition to the trapezoidal portion 62. The extending portion 66 has a flat portion 67 that expands in contact with the bottom surface of the fuel gas discharge manifold hole 42. And the water absorption member 68 for a connection is arrange | positioned so that it may overlap on this plane part 67 in the anode side plate part of each cell. Accordingly, as shown in the cross-sectional view of FIG. 4B, the water absorbing member 60C extending from the anode side plate 20 of each cell can be connected in the stacking direction of the stacked body 10C. The coupling water absorbing member 68 may be placed below the flat portion 67.

  By adopting this configuration, moisture transferred from the outlet header 48 into the fuel gas discharge manifold hole 42 via the water absorbing member moves to the adjacent water absorbing member 60B one after another due to the water gradient of the water absorbing member 60B. The gas moves through the gas discharge manifold hole 42 and is quickly discharged out of the stacked body 10B.

  In the first to third embodiments described above, the water absorbing members 60 </ b> A to 60 </ b> C are arranged so as to be in contact with the lower end of the fuel gas passage groove 22. Next, an embodiment having a configuration different from those of the first to third embodiments will be described.

Embodiment 4 FIG.
FIGS. 6A and 6B are diagrams illustrating the configuration of the polymer electrolyte fuel cell stack according to Embodiment 4. FIG. FIG. 6A is a plan view of the anode side plate 20, and FIG. 6B is a cross-sectional view taken along a line AA ′ in FIG. 6A of a part of the stacked body 10D of the polymer electrolyte fuel cell stack. It is sectional drawing cut out. Since the basic configuration of the stacked body 10D is the same as that of the stacked body 10A of the first embodiment, detailed description is omitted by giving the same reference numerals to the same members.

  In the fourth embodiment, the tunnel flow path forming plate 90 is provided with a small through hole 92 for each fuel gas flow path groove. Further, a trapezoidal window is formed in the tunnel flow path forming plate 90, and the trapezoidal portion of the second water absorbing member 60D is fitted therein. The 1st water absorption member 94 is arrange | positioned so that the through-hole 92 of the tunnel flow path formation plate 90 may be covered, and it may overlap with 2nd water absorption member 60D (refer FIG. 7). The shape of the second water absorbing member 60D is the same as the water absorbing member 60A in the first embodiment. The tunnel flow path forming plate 90 may be provided with a slit for each fuel gas flow path groove 22 instead of the through hole.

  In the above configuration, the water generated in the fuel gas channel groove 22 travels downward in the vertical direction along the tunnel channel forming plate 90, and the through-hole 92 formed in the tunnel channel forming plate 90. First, it is absorbed by the first water absorbing member 94. Next, it is absorbed by the second water absorbing member 60D in contact with the first water absorbing member 94. Then, the water flows due to the water gradient of the water absorbing member 60 </ b> D, and the water is discharged into the fuel gas discharge manifold hole 42.

  The form in which the water absorbing member is arranged on the upper side of the tunnel flow path forming plate is not limited to the configuration of the fourth embodiment. Embodiments 5 and 6 described below have the same configuration as that of Embodiment 4 except that the shape of the water absorbing member is different. Therefore, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same member.

Embodiment 5 FIG.
FIGS. 8A and 8B are diagrams illustrating the configuration of the polymer electrolyte fuel cell stack according to Embodiment 5. FIG. FIG. 8A is a plan view of the anode-side plate 20, and FIG. 8B is a cross-sectional view taken along a line AA ′ in FIG. 8A of a part of the stacked body 10E of the polymer electrolyte fuel cell stack. It is sectional drawing cut out. In the fifth embodiment, the second water absorbing member 60E has the same shape as the water absorbing member 60B shown in FIG. That is, the second water absorbing member 60 </ b> E has an extending portion 64 that extends into the fuel gas discharge manifold hole 42 in addition to the trapezoidal portion 62. The extending portion 64 is bent before coming into contact with the bottom surface of the fuel gas discharge manifold hole 42, and the extending portion of the water absorbing member 60 </ b> E extending from the anode side plate 20 of the adjacent cell is ahead of the bent portion. 64 has a length sufficient to contact 64. Accordingly, as shown in the cross-sectional view of FIG. 8B, the water absorbing member 60E extending from the anode side plate 20 of each adjacent cell is brought into contact with each other, thereby connecting the water absorbing member in the stacking direction of the stacked body 10E. be able to. The movement of the water generated in the fuel gas channel groove 22 is the same as that in the second embodiment.

Embodiment 6 FIG.
FIGS. 9A and 9B are diagrams illustrating the configuration of the polymer electrolyte fuel cell stack according to Embodiment 2. FIG. FIG. 9A is a plan view of the anode-side plate 20, and FIG. 9B is a cross-sectional view taken along a line AA ′ in FIG. 9A of a part of the solid polymer fuel cell stack 10F. It is sectional drawing cut out. In the sixth embodiment, the second water absorbing member 60F has the same shape as the water absorbing member 60C shown in FIG. That is, the water absorbing member 60 </ b> F has an extending portion 66 extending into the fuel gas discharge manifold hole 42 in addition to the trapezoidal portion 62. The extending portion 66 has a flat portion 67 that expands in contact with the bottom surface of the fuel gas discharge manifold hole 42. And the water absorption member 68 for a connection is arrange | positioned so that it may overlap on this plane part 67 in the anode side plate part of each cell. Accordingly, as shown in the cross-sectional view of FIG. 9B, the water absorbing member 60F extending from the anode side plate 20 of each cell can be connected in the stacking direction of the stacked body 10F. The movement of the water generated in the fuel gas channel groove 22 is the same as that in the third embodiment.

  The present invention has been described based on some embodiments. The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. The form can also be included in the scope of the present invention.

  In the embodiment, the anode side plate has been described as an example, but the present invention can be similarly applied to the case where moisture is supplied to the cathode side plate together with the oxidizing gas.

  Further, even in a fuel cell using an electrolyte body other than the solid polymer electrolyte membrane as an electrolyte body, by applying the water absorbing member described above to the cathode side plate, the reaction product water generated by the reaction in the fuel cell can be used. The influence of water clogging can be reduced.

  In the embodiment, the fuel gas flow channel groove formed in the anode side plate has been described as being arranged with the gas flow direction set to the lower side in the vertical direction. However, the fuel gas flow channel groove is not necessarily arranged in the vertical direction. It is not necessary to be arranged and may be arranged in an oblique direction. In the embodiment, the description has been given of the case where the outlet header is provided at the lower end of the fuel gas passage groove or the oxidant gas passage groove. However, the outlet header is not provided, and the fuel gas passage groove is provided. Alternatively, in a fuel cell stack having an anode side plate or a cathode side plate shaped so that the oxidant gas flow channel groove opens directly into the gas discharge manifold hole, it protrudes from the lower end of the gas flow channel groove to the gas discharge manifold hole. By providing such a water-absorbing member, the present invention can be applied.

(A) is a top view of the anode side plate which concerns on Embodiment 1, (b) is sectional drawing of the fuel cell stack which concerns on Embodiment 1. FIG. (A) is a top view of the anode side plate which concerns on Embodiment 2, (b) is sectional drawing of the fuel cell stack which concerns on Embodiment 2. FIG. It is a figure which shows the shape of the water absorption member which concerns on Embodiment 2. FIG. (A) is a top view of the anode side plate which concerns on Embodiment 3, (b) is sectional drawing of the fuel cell stack which concerns on Embodiment 3. FIG. (A) is a figure which shows the shape of the water absorbing member which concerns on Embodiment 3, (b) is a figure explaining the superposition of a water absorbing member. (A) is a top view of the anode side plate which concerns on Embodiment 4, (b) is sectional drawing of the fuel cell stack which concerns on Embodiment 4. FIG. It is a figure which shows the shape of the water absorption member which concerns on Embodiment 4. FIG. (A) is a top view of the anode side plate which concerns on Embodiment 5, (b) is sectional drawing of the fuel cell stack which concerns on Embodiment 5. FIG. (A) is a top view of the anode side plate which concerns on Embodiment 6, (b) is sectional drawing of the fuel cell stack which concerns on Embodiment 6. FIG.

Explanation of symbols

  10A to 10F Fuel cell stack, 20 Anode side plate, 22 Fuel gas channel groove, 30 Tunnel channel forming plate, 32 Fuel gas supply manifold hole, 34 Cooling water supply manifold hole, 36 Oxidant gas supply manifold hole, 38 Inlet header, 40 Tunnel flow path forming plate, 42 Fuel gas discharge manifold hole, 44 Cooling water discharge manifold hole, 46 Oxidant gas discharge manifold hole, 48 Outlet header, 54 Gasket, 58 Cooling water flow path, 60A-60C Water absorbing member 60D-60F 2nd water absorption member, 62 header part, 64, 66 extension part, 67 plane part, 68 water absorption member for connection, 70 MEA, 72 anode, 74 cathode, 76 solid polymer electrolyte membrane, 80 cathode side plate , 82 oxidizing gas passage grooves 90 tunnel flow path forming plate, 92 through hole, 94 the first water-absorbing member.

Claims (7)

A membrane electrode assembly in which an anode is disposed on one surface of the electrolyte membrane and a cathode is disposed on the other surface, an anode side plate in which an anode gas flow channel facing the anode is formed, and a cathode gas facing the cathode A fuel cell comprising a laminate in which a plurality of cells composed of a cathode side plate formed with a flow path is laminated, and a gas exhaust manifold penetrating the laminate is formed in the anode side plate and the cathode side plate A stack,
The cell further includes a water absorbing member disposed downstream of at least one of the anode gas channel and the cathode gas channel, and the water absorbing member has an extending portion extending into the gas discharge manifold. A fuel cell stack characterized by A membrane electrode assembly in which an anode is disposed on one surface of the electrolyte membrane and a cathode is disposed on the other surface, an anode side plate in which an anode gas flow channel facing the anode is formed, and a cathode gas facing the cathode A fuel cell comprising a laminate in which a plurality of cells composed of a cathode side plate formed with a flow path is laminated, and a gas exhaust manifold penetrating the laminate is formed in the anode side plate and the cathode side plate A stack,
The cell covers at least one of the anode gas channel or the cathode gas channel so as to face the channel bottom, and a tunnel channel forming plate provided with an opening corresponding to each gas channel; And a water absorbing member disposed on the tunnel flow path forming plate and covering the opening.   The fuel cell stack according to claim 2, wherein the water absorbing member has an extending portion that extends into the gas discharge manifold.   4. The fuel cell stack according to claim 1, wherein the extending portions of the water absorbing members of the cells are connected to each other in the gas discharge manifold.   5. The fuel cell stack according to claim 4, wherein the extended portion is bent in the gas discharge manifold, and the bent portion is in contact with an extended portion of a water absorbing member of an adjacent cell. The extension is bent in the gas discharge manifold;
5. The fuel cell stack according to claim 4, further comprising a connection water absorbing member that extends in a stacking direction of the gas discharge manifold and contacts an extending portion of the water absorbing member of each cell.   The fuel cell stack according to any one of claims 1 to 6, wherein the water absorbing member is formed in accordance with a shape of a gas outlet portion of the anode side plate or the cathode side plate.

Images