JP2001325971A - Solid polymer electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell in which performance of a separator of a solid polymer electrolyte fuel cell is prevented from being blocked by water droplets in a gas flow groove and performance is not reduced. SOLUTION: A polymer electrolyte fuel cell is manufactured using a separator 14 provided with a projection 40 and dividing a gas flow groove 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer electrolyte fuel cell using a polymer electrolyte membrane, and more particularly to a shape and a structure of a reaction gas flow groove formed in a separator constituting the battery.

[0002]

2. Description of the Related Art FIG. 1 is a longitudinal sectional view showing a basic structure of a unit cell of a solid polymer electrolyte fuel cell. As shown in FIG. 1, a fuel electrode 12 and an oxidant electrode 13 are arranged on both sides of a solid polymer electrolyte membrane 11, and a fuel gas is supplied to the fuel electrode 12 and an oxidant gas is supplied to the oxidant electrode 13 on both outer sides thereof. And a cooling water flow groove 16 for flowing cooling water to maintain the battery at an appropriate temperature.
Is disposed. The separator 14 is arranged so that the reaction gas flow groove 15 faces the fuel electrode 12 or the oxidant electrode 13. In FIG. 1, the separator 14, the fuel electrode 12, and the oxidizer electrode 13
However, in practice, the separator 14 is connected to the fuel electrode 12 and the oxidizer electrode 1 via the gas seal 17.
3 and is used as a unit cell that maintains the gas tightness of the gas flow portion.

FIG. 2 is a schematic side view of a fuel cell stack obtained by stacking the unit cells shown in FIG. Cell 21
, A current collecting plate 22 is disposed at both ends thereof, and an insulating plate 23 having an electric insulating function is disposed outside the current collecting plate 22. The insulating plate 23 is sandwiched by a tightening plate 24, and a tightening bolt 25, a disc spring 26 and It is tightened by using a tightening nut 27, and is pressed and held. FIG. 3 shows a separator 1 constituting the unit cell shown in FIG.
FIG. 4 is a perspective view of the electrode 4 viewed from a side facing an electrode. At the center of the separator 14 facing the fuel electrode 12 or the oxidant electrode 13, a plurality of gas circulation grooves 31 are arranged in parallel. A fuel gas such as hydrogen, which is a reaction gas supplied from the outside, or an oxidizing gas such as air is injected from a gas injection manifold hole 32 provided on the upstream side, sent to an inlet side manifold 35 and distributed, The gas flows from the upstream side to the downstream side in the gas flow groove 31 and is discharged to the outside through the gas discharge manifold hole 33. Adjacent gas flow groove 31
Are separated by a rib 34.

As the solid polymer electrolyte membrane, a polystyrene-based cation exchange membrane having a sulfonic acid group is used as a cation conductive membrane, a mixed membrane of fluorocarbon sulfonic acid and polyvinylidene fluoride, or trifluorocarbon matrix is used. Graphitized fluoroethylene, perfluorocarbon sulfonic acid (Nafion membrane manufactured by DuPont, USA) and the like are used. These solid polymer electrolyte membranes have a hydrogen ion exchange group in the molecule, and have a specific resistance of 20 Ω when saturated with water at normal temperature.
cm or less, and functions as a proton conductive electrolyte. Also, the saturated water content of the membrane changes reversibly with temperature.

The fuel electrode and the oxidizer electrode both comprise a catalyst layer and an electrode substrate supporting the catalyst layer, and the catalyst layer side is disposed in close contact with the solid polymer electrolyte membrane. One in which the solid polymer electrolyte membrane, the catalyst layer and the electrode substrate are arranged in close contact with each other is called a membrane electrode assembly (MEA). When hydrogen as a fuel gas is supplied to the fuel electrode 12 and oxygen or air as an oxidant gas is supplied to the oxidant electrode 13, a three-phase interface is formed at the interface between each catalyst layer, the solid polymer electrolyte membrane, and the gas. And the following electrical chemical reactions occur: Fuel electrode: H ₂ → 2H ⁺ + 2e ⁻ (1) Oxidizer electrode: 2H ⁺ + 1 / 2O ₂ + 2e ⁻ → H ₂ O (2) In this reaction, hydrogen and oxygen react to generate water. The catalyst layer is generally formed of a fine particulate platinum catalyst and a water-repellent fluororesin, and has pores formed so that the reaction gas can efficiently diffuse to the three-phase interface.

Since the voltage generated in each cell by this reaction is about 0.7 to 1.0 volt, in order to increase the voltage to a practical level, a large number of cells are stacked as shown in FIG. To form and use a fuel cell stack. FIG.
FIG. 2 is a schematic longitudinal sectional view of a fuel cell stack obtained by stacking the unit cells shown in FIG. 1. Further, in order to keep the specific resistance of the solid polymer electrolyte membrane low and to maintain the power generation efficiency high, usually 5
It is used at an operating temperature of 0-100 ° C, preferably 70-90 ° C. As described above, in the solid polymer electrolyte fuel cell, the specific resistance of the solid polymer electrolyte membrane is reduced by saturating water, and the membrane functions as a hydrogen ion conductive electrolyte. Therefore, in order to maintain the power generation efficiency of the polymer electrolyte fuel cell, it is necessary to maintain the water-containing state of the membrane to be saturated. For this reason, a method has been adopted in which water is supplied to the reaction gas to increase the humidity of the reaction gas and supply the reaction gas to the fuel cell, thereby suppressing evaporation of water from the film to the gas and preventing the film from drying.

[0007]

However, as shown in the above-mentioned chemical reaction formulas (1) and (2), water is generated as a reaction product when the fuel cell generates power, and this reaction water is generated in excess. Is discharged to the outside of the fuel cell together with the reaction gas. For this reason, the amount of moisture contained in the reaction gas in the unit cell is different between the upstream side and the downstream side in the flow direction of the reaction gas, and the downstream side, ie, the outlet side, is compared with the upstream side, ie, the entrance side of the reaction gas. Thus, a large amount of water is contained by an amount corresponding to the water produced by the reaction. Therefore, when the reaction gas humidified to the saturated state is supplied to the unit cell in order to maintain the water-containing state of the membrane to be saturated, the steam becomes supersaturated at the outlet side, and becomes mixed as water droplets at the outlet side. In addition, the water vapor stagnates as water droplets inside the gas flow groove of the separator, which becomes a flow path of the reaction gas, and further causes a situation in which the flow path is obstructed by blocking the flow path, or a reaction gas supply amount. May be insufficient or battery characteristics may be degraded.

When the width of the gas flow groove is large, ME
A hangs down in the gas flow grooves, blocking the gas flow grooves and obstructing the gas flow, resulting in a problem that the supply amount of the reaction gas may be insufficient or the battery characteristics may be deteriorated. Therefore, the present invention provides a means for efficiently discharging water droplets generated as a result of a chemical reaction, particularly on the downstream side of a gas circulation groove, to the outside of a fuel cell in order to solve the above-mentioned problems. An object of the present invention is to realize a solid polymer electrolyte fuel cell that can be distributed uniformly.

[0009]

According to the present invention, there is provided a unit cell comprising a solid polymer electrolyte membrane and a pair of electrodes sandwiching the solid polymer electrolyte membrane, wherein a fuel gas is supplied to and discharged from one of the electrodes. A solid polymer electrolyte fuel cell stacked via a conductive separator having a gas flow groove and a conductive separator having a gas flow groove for supplying and discharging an oxidizing gas to the other of the electrodes, wherein the conductive separator is ,
The present invention relates to a solid polymer electrolyte fuel cell having different numbers of gas flow grooves on an upstream side and a downstream side of a gas flow, and all the gas flow grooves are continuous. In the conductive separator, it is effective that the number of gas flow grooves on the downstream side of the gas flow is larger than the number of gas flow grooves on the upstream side.

[0010] The present invention also provides a cell comprising a solid polymer electrolyte membrane and a pair of electrodes sandwiching the solid polymer electrolyte membrane, comprising a gas flow groove for supplying and discharging fuel gas to one of the electrodes. A solid polymer electrolyte fuel cell stacked via a conductive separator having a gas flow groove for supplying and discharging an oxidizing gas to the other of the conductive separator and the electrode, wherein at least a part of the gas flow groove The present invention also relates to a solid polymer electrolyte fuel cell, wherein a projection is provided, and the gas flow groove is divided into a plurality. It is effective that the cross-sectional area of the protrusion in the direction perpendicular to the gas flow direction in the gas flow groove increases toward the downstream side. It is effective that the projection is electrically conductive, and it is effective that the projection is made of silicone rubber.
In addition, it is effective that the height of the protrusion is smaller than the depth of the gas flow groove, and that the gas flows through the upper surface of the protrusion. In the solid polymer electrolyte fuel cell, It is effective that the flow groove has water repellency, and the water repellency of the downstream portion is higher than the upstream portion of the gas flow groove. It is effective that the conductive separator is made of austenitic stainless steel.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In an embodiment of the present invention, an electrode layer is disposed on both main surfaces of an electrolyte layer comprising a polymer electrolyte membrane, and separators having gas flow grooves are disposed on both outer surfaces thereof. A solid polymer electrolyte in which a fuel cell is formed by stacking the unit cells, and a fuel gas flows through a gas flow groove of one separator and an oxidizing gas flows through a gas flow groove of the other separator. (1)
Each separator has a plurality of gas circulation grooves, and the number of gas circulation grooves is different between the upstream side and the downstream side of the gas. (2) In the gas circulation grooves of the separator, the number of gas circulation grooves on the downstream side is (3) A projection is provided on the downstream side of the gas flow groove of the separator, which is larger than the number of gas flow grooves on the side, and the gas flow groove is divided into at least two or more. Further, in the above configuration (3), (a) the occupied cross-sectional area of the gas flow groove of the separator of the protrusion is increased toward the downstream side, (b) the protrusion has conductivity, (c) The height of the protrusion is smaller than the height of the current collector of the separator.

The projection may be made of the same material as the separator. In this case, the separator having the projection may be formed by integral molding. In addition, the protrusion may be attached after a separator having a conventional shape is manufactured. in this case,
The material constituting the projection is not particularly limited as long as it is not deteriorated by the flowing reaction gas, and examples thereof include acrylic resin and silicone rubber. In addition, it is preferable to impart conductivity to the projections in order not to increase the contact resistance between the cells. In this case, for example, a conductive filler may be mixed. By setting the gas flow groove of the separator to the above configuration, the drainage efficiency of the generated water is improved particularly on the downstream side where water droplets are likely to stay, so that the reaction gas can flow stably, and the solid polymer electrolyte fuel It is possible to suppress a decrease in battery performance.

Such an effect is obtained by the following operation. That is, in the above configurations (1) to (3),
Since the cross-sectional area of the gas flow groove on the downstream side is small, the gas flow rate per unit area on the downstream side where the water droplets stay is increased. As a result, the drainage efficiency of the water droplet is increased by the increased gas flow rate, and the water droplet is guided to a predetermined outlet without remaining in the gas circulation groove. In consideration of the fact that water droplets are more likely to stay on the downstream side, drainage efficiency is further improved by adopting the above-mentioned (3) (a) configuration in which the occupied cross-sectional area of the projection increases toward the downstream side. . Since the protrusion has conductivity, the conductivity of the separator itself is not reduced, and there is no effect on battery performance. Even if the projections do not have conductivity, the configuration of (c) in (3) above does not directly affect the conductivity of the separators themselves, so that the battery performance is affected. There is no.

Further, when the surface of the gas flow groove of the separator is subjected to the water repellent treatment on the downstream side, the drainage efficiency is further improved.
This is because the contact angle of the water droplet with respect to the gas flow groove surface becomes large, so that the adhesion to both interfaces (gas flow groove / water droplet interface) is reduced, and the binding force of the water droplet to the gas flow groove surface is reduced. It is. Embodiments of the present invention will be described with reference to the drawings in order to clarify the configuration and operation of the present invention described above.

[0015]

Example 1 In this example, a solid polymer electrolyte fuel cell was manufactured using a unit cell having the structure shown in FIG. Fuel electrode 1 sandwiching solid polymer electrolyte membrane 11
A separator 14 having a gas flow groove 15 for flowing a reaction gas is disposed on both outer surfaces of the fuel cell 2 and the oxidant electrode 13 such that the reaction gas flow groove 15 faces the fuel electrode 12 or the oxidant electrode 13. , And was kept airtight by a gas seal body 17. In this example, a Nafion membrane (manufactured by DuPont) was used as the solid polymer electrolyte membrane 11. Here, the separator 14 on the side of the fuel electrode 12 and the side of the oxidant electrode 13 are obtained by placing a mixture of carbon powder and a phenol resin in a mold, and compression-molding the mixture while heating.

FIG. 4 is a partial schematic perspective view of the gas flow groove 15 of the separator 14 used in the present invention. FIG. 5 is a perspective view of the separator 14 having the gas flow grooves shown in FIG. As shown in FIGS. 4 and 5, a projection 40 is provided at the center in the width direction of the gas flow groove from the center of the gas flow toward the downstream side, and the number of gas flow grooves on the downstream side is increased from that on the upstream side. . With such a configuration, even if the moisture of the reaction gas humidified to the saturated state and the reaction water generated during the power generation of the fuel cell adhere to the gas circulation groove on the downstream side of the separator 14 as a water droplet, the gas circulation Since the downstream area of the groove 15 had a small cross-sectional area and an increased gas flow rate, water droplets did not stay in the gas flow groove.

Embodiment 2 Also in this embodiment, a solid polymer electrolyte fuel cell composed of a unit cell having the structure shown in FIG. 1 was manufactured. On both outer surfaces of the fuel electrode 12 and the oxidant electrode 13 sandwiching the solid polymer electrolyte membrane 11, a separator 14 having a gas flow groove 15 for flowing a reaction gas is formed. It was arranged so as to face the electrode 13 and was kept airtight by a gas seal body 17. As the solid polymer electrolyte membrane 11, a Nafion membrane (manufactured by DuPont, model number 112) was used. Here, as a separator on the fuel electrode side and the oxidant side, a mixture of carbon powder and a phenol resin was placed in a mold, and compression-molded with heating to produce a separator 14 having a structure shown in FIG.
Next, as shown in FIG. 6, a projection 41 made of a mixture of an acrylic resin and a conductive filler is formed downstream from the center of the gas flow in the gas flow groove 15, and the gas flow groove is formed at the center in the width direction. Divided by division. FIG. 6 is a partial schematic perspective view of the gas circulation groove 15 of the separator 14 used in the present embodiment. FIG. 7 shows a perspective view of the separator 14 manufactured in this embodiment.

During operation of the battery, in order to maintain the water content of the solid polymer electrolyte membrane 11 at saturation, the moisture of the reaction gas and the moisture of the reaction product supplied in a saturated humidified state are:
There is a possibility that the liquid will be supersaturated and liquefied, and will adhere to the gas flow grooves on the downstream side of the separator 14 as water droplets. However, in the fuel cell according to the present embodiment, the gas flow grooves 1
On the downstream side of 5, the projections reduced the gas flow groove cross-sectional area and increased the gas flow rate, so that the water droplets were guided to a predetermined flow path without remaining in the gas flow grooves. In addition, the risk of insufficient supply of the reaction gas was avoided, and the reaction gas could be stably and uniformly circulated.

Example 3 Also in this example, a solid polymer electrolyte fuel cell comprising a single cell having the structure shown in FIG. 1 was manufactured. On both outer surfaces of the fuel electrode 12 and the oxidizer electrode 13 sandwiching the solid polymer electrolyte membrane 11, a separator 14 having a gas flow groove 15 is provided so that the gas flow groove 15 faces the fuel electrode 12 or the oxidizer electrode 13. Gas seal body 1
7 to keep the airtight. In this embodiment, a Nafion membrane (manufactured by DuPont) is used as the solid polymer electrolyte membrane 11.
Was used. Here, the separator 14 on the fuel electrode side and the oxidizing agent side was prepared by placing a mixture of carbon powder and a phenol resin in a mold and performing compression molding while heating, thereby producing the separator 14 shown in FIG. Then, as shown in a partial schematic perspective view of the gas flow groove 15 in FIG. 8, a protrusion 42 made of an acrylic resin is formed on the gas flow groove 15 from the center of the gas flow to the downstream side, and the gas flow groove is divided. . Further, the projections 42 become closer to the downstream side,
The area occupying is increased. FIG. 9 shows a perspective view of the separator 14 having the gas flow grooves shown in FIG.

Fuel electrode side and oxidant side separator 14
Is obtained by placing a mixture of carbon powder and a phenol resin in a fixed mold and compressing the mixture while heating, and a projection 42 formed of an acrylic resin is provided on the downstream side of the gas flow groove 15. The gas flow groove 15 is divided as shown in FIGS. Further, the area of the protrusion 42 occupying the gas flow groove 15 increases toward the downstream side. Also, the height L ₂ from the bottom surface of the gas flow channel of the protruding portion 42 lower than the height L ₁ of the ribs 34 is a collector portion of the separator 14. In this embodiment, in order to maintain the water-containing state of the solid polymer electrolyte membrane 11 at saturation, the moisture of the reaction gas supplied by humidification to the saturated state and the moisture of the reaction water generated during power generation of the fuel cell Is liquefied in a supersaturated state, and the separator 14
Even if a situation occurs in which water droplets adhere to the gas flow groove 15 on the downstream side of the gas flow path, since the cross-sectional area of the gas flow groove is reduced and the flow rate is increased on the downstream side of the gas flow groove 15 by the projections 42, Was guided to a predetermined flow path without remaining in the gas circulation groove, and the risk of insufficient supply of the reaction gas was avoided, and the reaction gas flowed stably and uniformly. In the configuration shown in FIG. 8, the cooling water circulation grooves 16 are provided in the separator 14 to cool the unit cells. However, the present invention is not limited to this, and other components other than the separator may have this cooling function. You may.

Example 4 Also in this example, a solid polymer electrolyte fuel cell composed of a unit cell having the structure shown in FIG. 1 was manufactured. On both outer surfaces of the fuel electrode 12 and the oxidizer electrode 13 sandwiching the solid polymer electrolyte membrane 11, a separator 14 having a gas flow groove 15 is provided so that the gas flow groove 15 faces the fuel electrode 12 or the oxidizer electrode 13. Gas seal body 1
7 to keep the airtight. In the present embodiment, a Nafion membrane (manufactured by DuPont,
Model No. 112) was used. In the present example, a gas flow groove 15 was provided on the surface of a stainless steel (SUS304) metal plate by press molding to produce a separator 14 having the shape shown in FIG. Subsequently, the solid polymer electrolyte membrane 1
The separator 14 is disposed on both outer surfaces of the fuel electrode 12 and the oxidant electrode 13 with the gas seal groove 1 facing the fuel electrode 12 or the oxidant electrode 13.
7 to keep the airtight.

Here, the gas flow grooves 15 of the separator 14
Inside, a protrusion 43 made of silicone rubber was formed by injection molding, and the gas flow groove 15 was divided. FIG.
Next, a perspective view of the separator 14 manufactured in this example is shown. As shown in FIG. 10, a projection 43 is provided at the center of the gas flow groove 31 from the upstream side to the downstream side.
In this embodiment, in order to maintain the water-containing state of the solid polymer electrolyte membrane 11 at saturation, the moisture of the reaction gas supplied by humidification to the saturated state and the moisture of the reaction water generated during power generation of the fuel cell Liquefies in a supersaturated state,
Even if water droplets adhere to the gas flow grooves of the separator 14, since the flow rate of the gas flow grooves 15 is increased by the projections 43, the water droplets do not stay in the gas flow grooves but flow to a predetermined flow path. As a result, the risk of insufficient supply of the reaction gas was avoided, and the reaction gas circulated stably and uniformly. In addition, since the membrane electrode assembly is supported by the protrusions 43 in the gas flow grooves, the membrane electrode assembly is uniformly held over the entire surface of the separator 14, does not hang down in the gas flow grooves, and there is a risk that the supply of the reaction gas is insufficient. The reaction gas was circulated stably and uniformly.

[0023]

As described above, according to the present invention, the electrode layers are disposed on both main surfaces of the proton conductive solid polymer electrolyte membrane, and the separators having the gas flow grooves are disposed on both outer surfaces thereof. A solid polymer electrolyte in which a fuel cell is formed by stacking the unit cells, and a fuel gas flows through a gas flow groove of one separator and an oxidizing gas flows through a gas flow groove of the other separator. The present invention relates to a fuel cell. (1) Each separator has a plurality of gas circulation grooves, and the number of gas circulation grooves differs between the upstream side and the downstream side of the gas. (2) In the gas circulation grooves of the separator, the downstream gas The number of the flow grooves is larger than the number of the gas flow grooves on the upstream side, and / or (3) a projection is provided on the downstream side of the gas flow grooves of the separator, and the gas flow grooves are divided into at least two or more. It is a feature. Further, in the above configuration (3), (a) the occupied cross-sectional area of the gas flow groove of the separator of the projection increases toward the downstream side, and (b) the projection has conductivity. And / or (c) the height of the projection is lower than the height of the rib serving as the current collector of the separator. As a result, blockage due to water droplets in the gas flow grooves is suppressed, and a solid polymer electrolyte fuel cell in which the reaction gas flows stably and uniformly is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a basic configuration of a unit cell of a solid polymer electrolyte fuel cell.

FIG. 2 is a schematic side view of a fuel cell stack obtained by stacking the unit cells shown in FIG.

FIG. 3 is a perspective view of a separator constituting a unit cell as viewed from a side facing an electrode.

FIG. 4 is a partial schematic perspective view of a gas flow groove of a separator used in Example 1.

FIG. 5 is a perspective view of a separator having a gas circulation groove shown in FIG. 4;

FIG. 6 is a partial schematic perspective view of a gas flow groove of a separator used in Example 2.

FIG. 7 is a perspective view of a separator having a gas flow groove shown in FIG. 6;

FIG. 8 is a partial schematic perspective view of a gas flow groove of a separator used in Example 3.

FIG. 9 is a perspective view of a separator having a gas circulation groove shown in FIG. 8;

FIG. 10 is a perspective view of a separator manufactured in Example 4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Solid polymer electrolyte membrane 12 Fuel electrode 13 Oxidizer electrode 14 Separator 15 Gas circulation groove 16 Cooling water circulation groove 17 Gas seal body 21 Single cell 22 Current collecting plate 23 Insulating plate 24 Tightening plate 25 Tightening bolt 26 Disc spring 27 Tightening nut 31 Gas flow groove 32 Manifold for gas injection 33 Manifold for gas discharge 34 Rib 40 Projection 41 Projection 42 Projection 43 Projection

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Tatsuto Yamazaki 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. F term (reference) 5H026 AA06 CC03 EE08 HH02

Claims (9)

[Claims] 1. A unit cell comprising a solid polymer electrolyte membrane and a pair of electrodes sandwiching said solid polymer electrolyte membrane, and a conductive separator having a gas flow groove for supplying and discharging fuel gas to one of said electrodes. And a solid polymer electrolyte fuel cell laminated via a conductive separator having a gas flow groove for supplying and discharging an oxidizing gas to the other of the electrodes, wherein the conductive separator is an upstream side and a downstream side of a gas flow. A solid polymer electrolyte fuel cell having different numbers of gas flow grooves on the side, and all gas flow grooves are continuous. 2. The solid polymer electrolyte fuel cell according to claim 1, wherein in the conductive separator, the number of gas flow grooves on the downstream side of the gas flow is larger than the number of gas flow grooves on the upstream side. . 3. A unit cell comprising a solid polymer electrolyte membrane and a pair of electrodes sandwiching said solid polymer electrolyte membrane, and a conductive separator having a gas flow groove for supplying and discharging fuel gas to one of said electrodes. And a solid polymer electrolyte fuel cell stacked via a conductive separator having a gas circulation groove for supplying and discharging an oxidizing gas to the other of the electrodes, wherein a projection is provided on at least a part of the gas circulation groove. And
A solid polymer electrolyte fuel cell, wherein the gas flow groove is divided into a plurality of grooves. 4. The solid polymer according to claim 3, wherein a cross-sectional area of the protrusion in a direction perpendicular to a gas flow direction in the gas flow groove increases toward a downstream side. Electrolyte fuel cell. 5. The solid polymer electrolyte fuel cell according to claim 3, wherein the protrusion is electrically conductive. 6. The solid polymer electrolyte fuel cell according to claim 3, wherein said projections are made of silicone rubber. 7. The solid height according to claim 3, wherein the height of the protrusion is smaller than the depth of the gas flow groove, and gas flows through the upper surface of the protrusion. Molecular electrolyte fuel cell. 8. The solid according to claim 1, wherein the gas flow groove has water repellency, and the water repellency is higher on the downstream side than on the upstream side of the gas flow groove. Polymer electrolyte fuel cell. 9. The method according to claim 1, wherein the conductive separator is made of austenitic stainless steel.
A solid polymer electrolyte fuel cell according to any one of claims 1 to 8.