JP2006147503A - Fuel cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell stack which prevents certainly occurrence of remaining water in the reactant gas communicating hole and can obtain stable power generation voltage with a simple and economical construction, and is capable of especially improving low-temperature starting performance. <P>SOLUTION: The fuel cell stack 10 is provided with a laminate 14 laminated with a plurality of fuel cells 12, and an internal manifold is constructed penetrating through the laminate 14 in lamination direction. A water absorption member 70 for discharging water is installed at the oxidizer gas exit communicating hole 36b. The water absorption member 70 has an inclined face 72 of which height becomes larger toward a first end plate 20a so that the quantity of retained water may increase from a second end plate 20b side toward the first end plate 20a side of the oxidizer gas exit communicating hole 36b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes a laminate in which an electrolyte / electrode structure provided with a pair of electrodes on both sides of an electrolyte and a separator are horizontally laminated, and the laminate extends in the lamination direction. The present invention relates to an internal manifold type fuel cell stack in which a reaction gas communication hole is formed.

  For example, a solid polymer fuel cell employs a solid polymer electrolyte membrane made of a polymer ion exchange membrane. This fuel cell is an electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode made of an electrode catalyst (electrode catalyst layer) and porous carbon (gas diffusion layer) are provided on both sides of a solid polymer electrolyte membrane, respectively. Is constituted by a power generation cell sandwiched between separators (bipolar plates). Usually, in a fuel cell, a fuel cell stack in which a predetermined number of power generation cells are stacked is used.

  In this type of fuel cell, the anode side electrode is supplied with a fuel gas (reactive gas), for example, a gas mainly containing hydrogen (hereinafter also referred to as hydrogen-containing gas), while the cathode side electrode An oxidant gas (reactive gas), for example, a gas mainly containing oxygen or air (hereinafter also referred to as oxygen-containing gas) is supplied. In the fuel gas supplied to the anode side electrode, hydrogen is ionized on the electrode catalyst and moves to the cathode side electrode side through the electrolyte membrane. Electrons generated during that time are taken out to an external circuit and used as direct current electric energy.

  In the above fuel cell, an internal manifold is often configured to supply a fuel gas and an oxidant gas, which are reaction gases, to the anode side electrode and the cathode side electrode of each of the stacked power generation cells. The internal manifold includes a reaction gas inlet communication hole and a reaction gas outlet communication hole that are provided so as to penetrate in the stacking direction of the power generation cells, and an inlet side of the reaction gas flow path for supplying the reaction gas along the electrode surface. The reaction gas inlet communication hole and the reaction gas outlet communication hole communicate with the outlet side.

  By the way, reaction product water generated during power generation is introduced into the oxidant gas outlet communication hole through which the oxidant gas flows in the stacking direction and the oxidant gas communication hole (reaction gas communication hole) which is the oxidant gas inlet communication hole. In some cases, stagnant water may exist in the oxidant gas communication hole. On the other hand, there is a possibility that stagnant water due to condensation or the like may be generated in a fuel gas outlet communication hole through which fuel gas flows in the stacking direction or a fuel gas communication hole (reaction gas communication hole) which is a fuel gas inlet communication hole. Accordingly, there is a problem that the oxidant gas communication hole and the fuel gas communication hole are easily reduced or blocked by the staying water, and the flow of the oxidant gas and the fuel gas is hindered to reduce the power generation performance.

  Therefore, for example, in the fuel cell stack disclosed in Patent Document 1, a plurality of cells 1 are stacked as shown in FIG. 10, and both ends of the stacked body of the plurality of cells 1 are end plates 2. It is pinched. One end plate 2 is connected to a gas supply pipe 3 for supplying fuel gas or oxidant gas and a gas exhaust pipe 4 for discharging the fuel gas or oxidant gas.

  The gas supply pipe 3 and the gas exhaust pipe 4 are provided with a water reservoir portion 5 for temporarily storing condensed water and generated water, and a drain pipe 7 is connected to the lower portion of the water reservoir portion 5 through an electromagnetic valve 6. Has been.

  An internal manifold 9 is formed in a fuel cell stack 8 in which a plurality of cells 1 are sandwiched between end plates 2. The inner manifold 9 has an inclined bottom surface by gradually widening the hole diameter toward the gas supply pipe 3 and the gas exhaust pipe 4. Thereby, the condensed water and generated water of the internal manifold 9 flow to the respective water reservoirs 5 along the inclination of the lower surface of the internal manifold 9, and the water of the water reservoir 5 is drained from the drain pipe 7 under the action of the electromagnetic valve 6. It is said that it will be discharged through.

Japanese Patent Laying-Open No. 2003-177871 (FIG. 3)

  However, in Patent Document 1 described above, an electromagnetic valve 6 is connected below each water reservoir 5, and control of the electromagnetic valve 6 is required, which complicates the entire system. As a result, there is a problem that the cost of the entire system increases and the reliability decreases.

  Moreover, since the amount of generated water increases toward the downstream side of the internal manifold 9, a water pool is likely to occur near the outlet side of the internal manifold 9. Therefore, even if the lower surface of the internal manifold 9 is provided with a slope, there is a possibility that the water remaining in the internal manifold 9 cannot be discharged well to the water reservoir 5. As a result, the stability of the power generation voltage of the fuel cell stack 8 is lowered, and in particular, there is a problem that the internal manifold 9 is blocked during a low temperature start.

  The present invention solves this type of problem, reliably prevents the generation of stagnant water in the reaction gas communication hole, obtains a stable power generation voltage with a simple and economical configuration, and particularly at a low temperature start. An object of the present invention is to provide a fuel cell system capable of improving the performance.

  The present invention includes an electrolyte / electrode structure in which a pair of electrodes are provided on both sides of an electrolyte, and a laminate in which separators are laminated in a horizontal direction, and the laminate is provided along a surface direction of the electrodes. An internal manifold type in which a reaction gas flow path for supplying a reaction gas is formed and a reaction gas communication hole is formed which communicates with the discharge side end or the supply side end of the reaction gas flow path and penetrates in the stacking direction It is a fuel cell stack.

  The fuel cell stack is provided in the reaction gas communication hole and includes a water absorption member for draining, and the water absorption member is maintained from one end of the reaction gas communication hole toward the other end on the open side. It is configured to increase the amount of water.

  Moreover, it is preferable that a water absorption member is set to the shape which has a big cross-sectional area toward the open side other end part from the obstruction | occlusion side one end part. For example, by changing the thickness continuously or intermittently, or by changing the width dimension continuously or intermittently, the other end on the open side where a large amount of moisture is easily generated with a simple and economical configuration. Water can be reliably discharged from the section.

  Furthermore, it is preferable that the water absorbing member is set at a high density from one end on the closing side to the other end on the opening side. For example, it is possible to increase the fiber density of the open-side other end of the fibers constituting the water-absorbing member by setting the thickness of the open-side other end smaller than that of the closed-side end. .

Furthermore, the water absorbing member is preferably composed of an organic material having a functional group of —OH, —COOH, —NH ₂ , —SO ₃ H, or an organic material containing an inorganic oxide-based additive. It is because it is excellent in hydrophilicity and drainage is improved well.

  In addition, a bar-like member that contacts the water-absorbing member and is exposed to the outside of the reaction gas communication hole in the horizontal direction or the downward direction is disposed at the other end of the open side, and the bar-like member has a hydrophilic surface. It is preferable to have. Therefore, since water is smoothly discharged through the rod-like member having excellent hydrophilicity, the drainage performance is further improved.

  Furthermore, the present invention includes a plurality of rod-shaped members that are disposed in the reaction gas communication hole and perform drainage, and the plurality of rod-shaped members have a hydrophilic surface and are open from the closed end to the open side. It arrange | positions so that a mutual space | interval may become large toward an edge part.

  According to the present invention, the water-absorbing member has a water retention amount that increases from one end of the reaction gas communication hole toward the other end on the open side. It is possible to effectively prevent water retention. Furthermore, an actuator such as a solenoid valve is not necessary.

  Moreover, in this invention, it becomes possible to aim at discharge | emission of a water | moisture content by generating a capillary phenomenon between several rod-shaped members. In addition, by changing the interval between the rod-like members, it is possible to prevent water from staying at the other end on the open side where a large amount of moisture is likely to be generated, and it is possible to have a good drainage function.

  As a result, the reaction gas communication hole is not clogged with stagnant water, and a stable power generation voltage can be obtained with a simple and economical configuration, and particularly low temperature startability can be improved.

  FIG. 1 is a partially sectional side view of a fuel cell stack 10 according to the first embodiment of the present invention, and FIG. 2 is a schematic perspective view of the fuel cell stack 10.

  The fuel cell stack 10 includes a stacked body 14 in which a plurality of fuel cells 12 are stacked. At both ends of the stacked body 14 in the stacking direction (arrow A direction), first and second terminal plates 16a and 16b, First and second insulating plates 18a and 18b and first and second end plates 20a and 20b are sequentially provided. Although not shown, the fuel cell stack 10 is clamped and held by, for example, a tightening bolt or a box-shaped casing.

  As shown in FIG. 3, the fuel cell 12 includes an electrolyte membrane / electrode structure 30, and first and second metal separators 32, 34 having a thin plate shape that sandwich the electrolyte membrane / electrode structure 30. Instead of the first and second metal separators 32 and 34, for example, a carbon separator may be adopted.

  An oxidant gas inlet communication hole (reactive gas communication hole) 36a for supplying an oxidant gas, for example, an oxygen-containing gas, communicates with each other in the arrow A direction at one end edge of the fuel cell 12 in the arrow B direction. A cooling medium inlet communication hole 38a for supplying a cooling medium and a fuel gas outlet communication hole (reaction gas communication hole) 40b for discharging a fuel gas, for example, a hydrogen-containing gas, are provided.

  The oxidant gas inlet communication hole 36a, the cooling medium inlet communication hole 38a, and the fuel gas outlet communication hole 40b have one end in the stacking direction (the other end on the open side) on the first end plate 20a side opened, while the second end plate The other end in the stacking direction on the 20b side (one end on the closing side) is closed.

  The other end edge of the fuel cell 12 in the direction of arrow B communicates with each other in the direction of arrow A, a fuel gas inlet communication hole (reaction gas communication hole) 40a for supplying fuel gas, and for discharging the cooling medium The cooling medium outlet communication hole 38b and the oxidant gas outlet communication hole (reaction gas communication hole) 36b for discharging the oxidant gas are provided.

  The fuel gas inlet communication hole 40a, the cooling medium outlet communication hole 38b, and the oxidant gas outlet communication hole 36b are opened at one end in the stacking direction on the first end plate 20a side, and the other end in the stacking direction on the second end plate 20b side. Is blocked.

  A fuel gas flow path (reactive gas flow path) 42 that connects the fuel gas inlet communication hole 40a and the fuel gas outlet communication hole 40b is formed on the surface 32a of the first metal separator 32 facing the electrolyte membrane / electrode structure 30. Is done. The fuel gas channel 42 is constituted by, for example, a plurality of grooves extending in the direction of arrow B. A cooling medium flow path 44 that connects the cooling medium inlet communication hole 38 a and the cooling medium outlet communication hole 38 b is formed on the surface 32 b of the first metal separator 32. The cooling medium flow path 44 is configured by a plurality of grooves extending in the arrow B direction.

  On the surface 34 a of the second metal separator 34 facing the electrolyte membrane / electrode structure 30, for example, an oxidant gas flow path (reactive gas flow path) 46 including a plurality of grooves extending in the direction of arrow B is provided. The oxidant gas passage 46 communicates with the oxidant gas inlet communication hole 36a and the oxidant gas outlet communication hole 36b. A cooling medium flow path 44 is integrally formed on the surface 34 b of the second metal separator 34 so as to overlap the surface 32 b of the first metal separator 32.

  A first seal member 48 is integrally formed on the surfaces 32 a and 32 b of the first metal separator 32 around the outer peripheral edge of the first metal separator 32. The first seal member 48 surrounds and communicates the fuel gas inlet communication hole 40a, the fuel gas outlet communication hole 40b, and the fuel gas flow path 42 with the surface 32a, while the surface 32b communicates with the cooling medium inlet communication hole 38a. The medium outlet communication hole 38b and the cooling medium flow path 44 are surrounded and communicated with each other.

  A second seal member 50 is integrally formed on the surfaces 34 a and 34 b of the second metal separator 34 around the outer peripheral edge of the second metal separator 34. The second seal member 50 surrounds and communicates the oxidant gas inlet communication hole 36a, the oxidant gas outlet communication hole 36b, and the oxidant gas flow path 46 at the surface 34a, while the cooling medium inlet communication hole at the surface 34b. 38a, the cooling medium outlet communication hole 38b, and the cooling medium flow path 44 are surrounded and communicated with each other.

  The electrolyte membrane / electrode structure 30 includes, for example, a solid polymer electrolyte membrane 52 in which a thin film of perfluorosulfonic acid is impregnated with water, and an anode side electrode 54 and a cathode side electrode 56 that sandwich the solid polymer electrolyte membrane 52. With.

  The anode side electrode 54 and the cathode side electrode 56 are uniformly coated with a gas diffusion layer (not shown) made of carbon paper or the like, and porous carbon particles carrying a platinum alloy on the surface thereof. And an electrode catalyst layer (not shown) formed. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 52.

  As shown in FIG. 2, pipe manifolds 60a and 62a communicating with the oxidant gas inlet communication hole 36a, the cooling medium inlet communication hole 38a, and the fuel gas outlet communication hole 40b on one end side in the arrow B direction are provided on the first end plate 20a. And 64b are attached via insulating grommets 66. For example, the piping manifold 64b is curved and inclined downward.

  On the other end side in the arrow B direction of the first end plate 20a, pipe manifolds 64a, 62b and 60b communicating with the fuel gas inlet communication hole 40a, the cooling medium outlet communication hole 38b and the oxidant gas outlet communication hole 36b are insulated grommets 66. It is attached via. The piping manifold 64a is curved and inclined downward, for example.

As shown in FIG. 4, a water absorbing member 70 for draining is disposed in the oxidant gas outlet communication hole 36b and the fuel gas outlet communication hole 40b. The water absorbing member 70 is composed of an organic material having a functional group of —OH, —COOH, —NH ₂ , or —SO ₃ H, or an organic material containing an inorganic oxide-based additive such as titanium oxide or magnesium oxide. Specifically, the water absorbing member 70 is composed of aramid fibers, nylon fibers, or ceramic-containing polyester fibers.

  The water absorbing member 70 is directed from the closed side one end (second end plate 20b side) to the open side other end (first end plate 20a side) of the oxidant gas outlet communication hole 36b and the fuel gas outlet communication hole 40b ( Arrow A1 direction) It has the inclined surface 72 whose height (thickness) becomes large. The water absorbing member 70 is set in a tapered shape having a large cross-sectional area toward the first end plate 20a, so that the water retention amount increases toward the first end plate 20a. Instead of the continuous inclined surface 72, a stepped surface whose thickness changes intermittently may be employed.

  An end portion of a rod-like member 74 that protrudes into the pipe manifolds 60b and 64b from the horizontal direction to the downward direction is inserted into the distal end portion in the arrow A1 direction of the water absorbing member 70. The rod-like member 74 is made of a material having a hydrophilic surface, for example, a material having a contact angle with water of 65 ° or less (metal material, for example, stainless steel), and has a desired hydrophilicity and has a desired drainage function. have.

  The operation of the fuel cell stack 10 configured as described above will be described below.

  First, as shown in FIG. 2, in the fuel cell stack 10, an oxidant gas such as an oxygen-containing gas is supplied from the pipe manifold 60a, and a fuel gas such as a hydrogen-containing gas is supplied from the pipe manifold 64a. Further, a cooling medium such as pure water or ethylene glycol is supplied from the piping manifold 62a. For this reason, oxidant gas, fuel gas, and a cooling medium are supplied to each fuel cell 12 in the direction of arrow A.

  As shown in FIG. 3, the oxidant gas is introduced from the oxidant gas inlet communication hole 36 a into the oxidant gas flow path 46 of the second metal separator 34, and along the cathode side electrode 56 of the electrolyte membrane / electrode structure 30. Move. On the other hand, the fuel gas is introduced into the fuel gas flow path 42 of the first metal separator 32 from the fuel gas inlet communication hole 40 a and moves along the anode side electrode 54 of the electrolyte membrane / electrode structure 30.

  Therefore, in each electrolyte membrane / electrode structure 30, the oxidant gas supplied to the cathode side electrode 56 and the fuel gas supplied to the anode side electrode 54 are consumed by an electrochemical reaction in the electrode catalyst layer, Power generation is performed.

  Next, the oxidant gas consumed by being supplied to the cathode side electrode 56 flows in the direction of arrow A along the oxidant gas outlet communication hole 36b, and is then discharged to the pipe manifold 60b (see FIG. 2). Similarly, the fuel gas consumed by being supplied to the anode electrode 54 is discharged to the fuel gas outlet communication hole 40b, flows in the direction of arrow A, and is discharged to the pipe manifold 64b.

  Further, as shown in FIG. 3, the cooling medium is introduced into the cooling medium flow path 44 between the first and second metal separators 32 and 34 from the cooling medium inlet communication hole 38a, and then flows along the arrow B direction. To do. The cooling medium cools the electrolyte membrane / electrode structure 30, and then moves through the cooling medium outlet communication hole 38b and is discharged to the pipe manifold 62b (see FIG. 2).

  In this case, in the first embodiment, as shown in FIGS. 1 and 4, a water absorbing member 70 is disposed in the oxidizing gas outlet communication hole 36b, and the water absorbing member 70 is connected to the first end plate 20a. A taper shape having a larger cross-sectional area is set, and the water retention amount is increased toward the first end plate 20a.

  For this reason, in the oxidant gas outlet communication hole 36b, it is possible to effectively prevent water from staying on the first end plate 20a side (the other end on the open side) where a large amount of water is likely to be generated. . In addition, an actuator such as a solenoid valve becomes unnecessary. As a result, the oxidant gas outlet communication hole 36b is not clogged with stagnant water, and with a simple and economical configuration, a stable power generation voltage can be obtained, and in particular, low temperature startability can be improved. The effect of becoming.

Furthermore, the water absorbing member 70 is made of an organic material having a functional group of —OH, —COOH, —NH ₂ , or —SO ₃ H, or an organic material containing an inorganic oxide-based additive. Therefore, the water-absorbing member 70 has an advantage that it is excellent in hydrophilicity and drainage performance is improved satisfactorily.

  Furthermore, a rod-shaped member 74 that contacts the water-absorbing member 70 and is exposed to the outside of the oxidant gas outlet communication hole 36b from the horizontal direction to the downward direction is disposed, and the rod-shaped member 74 has a contact angle with water. Is made of a material of 65 ° or less. Therefore, the rod-shaped member 74 is excellent in hydrophilicity, and the moisture in the oxidant gas outlet communication hole 36b is smoothly discharged to the pipe manifold 60b through the rod-shaped member 74, so that the drainage performance is further improved.

  The fuel gas outlet communication hole 40b is provided with a water absorbing member 70 and a rod-shaped member 74. The fuel gas outlet communication hole 40b also has the same effect as the oxidant gas outlet communication hole 36b. It is done.

  FIG. 5 is a perspective view illustrating a main part of a fuel cell stack 80 according to the second embodiment of the present invention. The same components as those of the fuel cell stack 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Similarly, in the third and fourth embodiments described below, detailed description thereof is omitted.

  The fuel cell stack 80 includes a water absorbing member 82 disposed in the oxidant gas outlet communication hole 36b and the fuel gas outlet communication hole 40b. The water absorbing member 82 is set to have a large cross-sectional area toward the first end plate 20a by having the inclined surface 84 whose width dimension increases toward the first end plate 20a. A rod-like member 74 is disposed at the end of the water absorbing member 82 on the maximum width dimension side (first end plate 20a side) as necessary. Instead of the inclined surface 84, a stepped surface whose width dimension changes intermittently may be employed.

  In the second embodiment, the water absorbing member 82 can increase the water retention amount toward the first end plate 20a. Thereby, it is possible to effectively prevent the water from staying on the first end plate 20a side where a large amount of water is likely to be generated, and the same effects as in the first embodiment can be obtained.

  FIG. 6 is a perspective view illustrating a main part of a fuel cell stack 90 according to the third embodiment of the present invention.

  The fuel cell stack 90 includes a water absorbing member 92 disposed in the oxidant gas outlet communication hole 36b and the fuel gas outlet communication hole 40b. The water absorbing member 92 is set with high density from the second end plate 20b toward the first end plate 20a.

  Specifically, the water absorbing member 92 is made of an aramid fiber, a nylon fiber, or a ceramic-containing polyester fiber, and an end 92a on the second end plate 20b side has an irregular cross section 94a as shown in FIG. And it is set to a relatively large diameter. On the other hand, the end 92b on the first end plate 20a side of the water absorbing member 92 is set to have a fiber thickness of about half of the cross section 94a and a mainly round cross section 94b, as shown in FIG.

  In the third embodiment, the water absorbing member 92 sets the fiber density higher toward the first end plate 20a. For this reason, it is possible to increase the amount of water retained toward the first end plate 20a, and to effectively prevent the water from staying on the first end plate 20a side where a large amount of water is likely to be generated. The same effects as those of the first and second embodiments can be obtained.

  FIG. 9 is an explanatory perspective view of main parts of a fuel cell stack 100 according to the fourth embodiment of the present invention.

  The fuel cell stack 100 includes a plurality of rod-like members 102 disposed in the oxidant gas outlet communication hole 36b and the fuel gas outlet communication hole 40b. An interval H between the rod-like members 102 is set so as to increase from the second end plate 20b toward the first end plate 20a. As the rod-shaped member 102, for example, a glass thin tube is used.

  In this 4th Embodiment, the space | interval H between each rod-shaped member 102 is large toward the 1st end plate 20a. For this reason, it is possible to generate capillary action in each rod-like member 102 to discharge moisture, and to effectively prevent water from staying on the first end plate 20a side where moisture is likely to be generated in particular. For example, the same effects as those of the first to third embodiments can be obtained.

1 is a partial cross-sectional side view of a fuel cell stack according to a first embodiment of the present invention. 2 is a schematic perspective view of the fuel cell stack. FIG. It is a disassembled perspective view of the fuel cell which comprises the said fuel cell stack. FIG. 3 is a perspective view illustrating a main part of the fuel cell stack. It is principal part perspective explanatory drawing of the fuel cell stack which concerns on the 2nd Embodiment of this invention. It is a principal part perspective explanatory view of the fuel electric stack concerning a 3rd embodiment of the present invention. It is one edge explanatory drawing of the water absorption member which comprises the said fuel cell stack. It is explanatory drawing of the other edge part of the said water absorbing member. It is principal part perspective explanatory drawing of the fuel cell stack which concerns on the 4th Embodiment of this invention. 1 is a schematic configuration explanatory diagram of a fuel cell stack of Patent Document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 80, 90, 100 ... Fuel cell stack 12 ... Fuel cell 14 ... Laminated body 20a, 20b ... End plate 30 ... Electrolyte membrane and electrode structure 32, 34 ... Metal separator 36a ... Oxidant gas inlet communication hole 36b ... Oxidation Agent gas outlet communication hole 38a ... Cooling medium inlet communication hole 38b ... Cooling medium outlet communication hole 40a ... Fuel gas inlet communication hole 40b ... Fuel gas outlet communication hole 42 ... Fuel gas flow path 44 ... Cooling medium flow path 46 ... Oxidant gas Flow path 52 ... Solid polymer electrolyte membrane 54 ... Anode side electrode 56 ... Cathode side electrodes 60a, 60b, 62a, 62b, 64a, 64b ... Piping manifolds 70, 82, 92 ... ... Bar-shaped members 94a, 94b ... Cross section

Claims (6)

An electrolyte / electrode structure in which a pair of electrodes are provided on both sides of the electrolyte, and a laminate in which a separator is laminated in a horizontal direction, and a reactive gas is supplied to the laminate along the surface direction of the electrode An internal manifold type fuel cell stack in which a reaction gas flow path is formed and a reaction gas communication hole that communicates with a discharge side end or a supply side end of the reaction gas flow path and penetrates in a stacking direction is formed. There,
A water-absorbing member disposed in the reaction gas communication hole for draining;
The fuel cell stack, wherein the water-absorbing member is configured such that the water retention amount increases from one end portion on the closed side of the reaction gas communication hole toward the other end portion on the open side.   2. The fuel cell stack according to claim 1, wherein the water absorbing member is set in a shape having a large cross-sectional area from one end of the closing side toward the other end of the opening side.   2. The fuel cell stack according to claim 1, wherein the water absorbing member is set at a high density from the one end on the closing side toward the other end on the opening side. 4. The fuel cell stack according to claim 1, wherein the water absorbing member is an organic material having a functional group of —OH, —COOH, —NH ₂ , —SO ₃ H, or an inorganic oxide type. 5. A fuel cell stack comprising an organic material containing an additive. 5. The fuel cell stack according to claim 1, wherein the other end of the open side contacts the water absorbing member and is exposed to the outside of the reaction gas communication hole in a horizontal direction or a downward direction. A rod-shaped member is disposed,
The fuel cell stack characterized in that the rod-shaped member has a hydrophilic surface. An electrolyte / electrode structure in which a pair of electrodes are provided on both sides of the electrolyte, and a laminate in which a separator is laminated in a horizontal direction, and a reactive gas is supplied to the laminate along the surface direction of the electrode An internal manifold type fuel cell stack in which a reaction gas flow path is formed and a reaction gas communication hole that communicates with a discharge side end or a supply side end of the reaction gas flow path and penetrates in a stacking direction is formed. There,
A plurality of rod-shaped members disposed in the reaction gas communication hole for draining;
The fuel cell stack, wherein the plurality of rod-shaped members have hydrophilic surfaces and are arranged such that a distance between the plurality of rod-shaped members increases from the closed side one end portion toward the open side other end portion. .

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