JPH08250130A - Solid polymer type fuel cell - Google Patents

Abstract

PURPOSE: To provide a solid polymer type fuel cell, wherein assembly is facilitated and performance is sharply improved, by forming a fuel electrode side collector out of a hydrophilic conductive porous body, and a humidifying water permeating body out of a water repellent porous body respectively. CONSTITUTION: Fuel and oxidant electrodes 101 and 102 are arranged on both the surfaces of a polymer electlyte membrane 100, and a fuel electrode side collector 105 having a fuel gas guide groove 106 and an oxidant electrode side collector 107 having an oxidant gas guide groove 108 are provided while contacting with the electrodes 101 and 102 to form a unit cell, and plurals of its are layered. A cooling plate 110 is inserted into the lower surface of the collector 105 via a humidifying water permeating body 109 composed of porous body at every single cell, to supply cooling water to the membrane 100 via the collector 105 and the electrode 101. At this time, the collector 105 is formed out of a hydrophilic carbon porous plate, having a porosity of about 70% and a mean hole diameter of about 40μm, and is provided with the groove 106; and the body 109 is formed out of a carbon porous thin plate, having a porosity of about 40% and a mean hole diameter of about 5μm, and water repellent treatment is applied.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a solid polymer using a polymer film having hydrogen ion conductivity or a composite material composed of a powder of an inorganic or organic material having hydrogen ion conductivity and a polymer binder as an electrolyte. Type fuel cell.

[0002]

2. Description of the Related Art In recent years, fuel cells have been attracting attention as a highly efficient energy conversion device. Fuel cells are, for example, alkaline aqueous solution type, depending on the type of electrolyte used for them.
It is roughly classified into low temperature operating fuel cells such as phosphoric acid type and solid polymer type, and high temperature operating fuel cells such as molten carbonate type and solid oxide electrolyte type.

Among these fuel cells, a polymer electrolyte membrane having a hydrogen ion conductivity as an electrolyte (Polymer Elec
A polymer electrolyte fuel cell using a trolyte Membrane)
Because it does not require a pressure vessel, it is compact and has a high power density, it has excellent startability, and it can be operated with a simple system. It is attracting attention for use in stationary and stationary applications.

As an electrolyte membrane used in a polymer electrolyte fuel cell, a polystyrene cation exchange membrane having a sulfonic acid group, a mixed substance of fluorocarbon sulfonic acid and polyvinylidene fluoride, and trifluoroethylene as a fluorocarbon matrix. Grafted products and the like are known. Recently, a perfluorocarbon sulfonic acid membrane (for example, Nafion: trade name, manufactured by DuPont) is also used.

A polymer electrolyte fuel cell using such a polymer electrolyte membrane has a pair of porous electrodes having a function as a gas diffusion layer and a catalyst layer, that is, a fuel electrode and an oxidant electrode. A single cell having a current collector having a fuel flow path and an oxidant flow path disposed on both outer sides of the single electrode, and a structure in which a plurality of such single cells are laminated via a cooling plate or the like. Has become.

That is, as shown in FIG. 19 as an example of a typical polymer electrolyte fuel cell, a fuel electrode 2 and an oxidizer electrode 3 (not shown) are arranged so as to sandwich a polymer membrane 1. Fuel pole 1
A porous fuel electrode side current collector plate 4 having a function as a fuel gas flow channel is disposed on the side, and a grooved oxidant electrode also having a function as an oxidant gas flow channel is provided on the oxidant electrode 2 side. Side current collector 5
To place. Then, a porous plate (cooling plate) 6 for holding the humidifying water is arranged on the fuel electrode side current collecting plate 4, a packing 7 for sealing is arranged around the fuel electrode 2, and oxidation is similarly performed. A packing 8 for sealing is arranged around the agent electrode 3.

A unit cell is formed by arranging the respective elements in this way, and a plurality of the unit cells are laminated to form a polymer electrolyte fuel cell. A separator 9 for separating each unit cell is inserted in the laminated body. Further, in the example of this figure, the fuel gas flow channel provided in the fuel electrode side current collector plate 4 and the oxidant gas flow channel formed by the groove in the oxidant electrode side current collector plate 5 are orthogonal to each other. An oxidant flow channel is opened on two opposing side surfaces of the stack. Further, the packing 7 is provided with manifold portions 10 and 11 (however, the manifold portion 11 is not shown) for supplying and discharging fuel.

End plates 12 are provided so as to overlap each other on both end faces of the laminated body. And these end plates 12
A tightening plate (not shown) larger than the end plate 12 is arranged on the outer side of the end plate 12, and the tightening plates and the tightening plates are tightened between the tightening plates by using a tightening rod and a spring. The thermal resistance is reduced. Pure oxygen or air is used as the oxidant gas, and pure hydrogen or a hydrogen-rich gas obtained by reforming natural gas or methanol is used as the fuel gas.

However, the conventional polymer electrolyte fuel cell constructed as described above has the following problems. (1) It is difficult to assemble a stack having almost the same electric constants As can be seen from FIG. 19, many parts are required to construct a polymer electrolyte fuel cell. If the number of parts is large in this way, not only the work when stacking and assembling a plurality of single cells becomes extremely difficult, but also it becomes difficult to assemble each part so that the contact resistance between each part is below a certain value, It is difficult to prepare multiple stacks with almost the same electrical constants,
There was a problem that the performance of the entire system deteriorated.

(2) Difficult to construct a desired humidification system A polymer membrane used as an electrolyte exhibits hydrogen ion conductivity in a state of containing water. It becomes an insulator when dried,
Does not function as an electrolyte. When it absorbs moisture to a saturated state, it exhibits the highest conductivity. In order to continue the electromotive reaction, it is necessary to prevent the polymer electrolyte membrane from drying and keep it in a water-containing state, that is, humidify it.

As a method of humidifying the polymer electrolyte membrane,
A so-called indirect humidification method in which steam is added to fuel gas or oxidant gas heated to a temperature higher than the cell temperature to condense and humidify in the cell, and a part of cooling water is porous plate (cooling plate) and porous fuel There is a direct humidification method in which it exudes into the fuel electrode through the electrode side current collector plate and directly humidifies.

However, in the indirect humidification method, it is necessary to heat the fuel gas and the oxidant gas to a temperature higher than the operating temperature of the cell, so that the efficiency cannot be avoided. On the other hand, in the direct humidification method, there is a problem in system integrity such that part of the cooling water leaks into the fuel electrode when the system is stopped, or conversely, fuel gas enters the cooling water. Also, during steady-state power generation at a constant current density, the water produced by the battery reaction diffuses from the oxidizer electrode to the polymer electrolyte membrane,
The polymer electrolyte membrane is sufficiently humidified. Therefore, in such a case, there is also a problem that the humidifying water becomes unnecessary and, as a result, the surplus humidifying water blocks the fuel electrode and the performance deteriorates.

Further, when the number of laminated single cells increases,
Due to the action of gravity, the amount of permeated water increases in the unit cell located in the lower part in the vertical direction, and when trying to put the upper part in an appropriate humidification state, the fuel gas flow path in the lower part is blocked with excess water,
On the contrary, there was a problem that when the lower part was made to have an appropriate humidification condition, insufficient humidification occurred at the upper part.

(3) Difficult to seal fuel gas, oxidant gas and cooling water As shown in FIG. 19, flat packings 7 and 8 are arranged around the fuel electrode 2 and the oxidant electrode 3, and these packings are arranged. Fuel gas, oxidant gas, and cooling water are sealed at 7 and 8, but it is extremely difficult to adjust the level difference between the flat packing and the electrode. That is, if the packings 7 and 8 are too thick, the fuel electrode 2 and the oxidant electrode 3 will not come into good contact with the fuel electrode side current collector plate 4 and the oxidant electrode side current collector plate 5, and the contact resistance will increase. Battery performance will decrease. On the other hand, if the electrodes are too thick, it is not possible to apply sufficient sealing surface pressure to the packings 7 and 8, which causes a leak of supply gas and cooling water. In addition, in the polymer electrolyte fuel cell, as shown in FIG.
As shown in FIG. 9, separator 9, packing 7, 8
It is common to employ an internal manifold configuration in which holes for supplying / discharging the supply gas and the cooling water are provided. In this case, the areas of the packings 7 and 8 are increased, and as a result, the cross-sectional area of the stack is increased and a large tightening force is required, and a tightening jig composed of studs, metal springs and the like becomes large in size. There was a problem.

[0015]

As described above, in the conventional polymer electrolyte fuel cell, it is difficult to structurally improve the cell performance. Therefore, an object of the present invention is to provide a polymer electrolyte fuel cell which is easy to assemble and whose performance can be significantly improved.

[0016]

In order to achieve the above object, in the first invention of the present invention, at least a polymer electrolyte membrane and a pair of gases provided in contact with both surfaces of the polymer electrolyte membrane are provided. A diffusion electrode, a pair of current collectors provided in contact with these gas diffusion electrodes and having a plurality of guide grooves for allowing a reactive gas to flow therethrough on a contact surface with the gas diffusion electrode, and a pair of current collectors. A unit cell having an internal manifold mechanism for distributing a reactive gas to the guide groove of the body, in a polymer electrolyte fuel cell in which a plurality of unit cells are laminated via a conductive separator plate, the separator plate and , A current collector outer frame that is adhesively fixed to at least one surface of the separator plate, and the current collector that is disposed in the current collector outer frame and fixed to the separator plate with a conductive adhesive, Current collector An internal manifold element that is disposed between the outer frame of the current collector and is fixedly adhered to the separator plate, and an opening that exposes the surface of the current collector on which the guide groove is formed to the outside It is characterized by comprising a separator unit including a manifold cover having a region for covering the manifold element and being fixedly adhered to the outer frame of the current collector.

It is preferable that the separator plate, the outer frame of the current collector, the current collector, the internal manifold element, and the manifold cover that constitute the separator unit are made of carbon.

Further, it is more preferable that the current collector and the manifold element are integrally formed. To achieve the above object, in a second aspect of the present invention, a polymer electrolyte membrane, a porous fuel electrode provided in contact with one surface of the polymer electrolyte membrane, and the polymer electrolyte A porous oxidant electrode provided in contact with the other surface of the membrane and a fuel gas formed in a conductive porous body in contact with the fuel electrode and provided in contact with the fuel electrode. A current collector on the fuel electrode side having a plurality of guide grooves for flowing through, and an oxidant gas provided on the contact surface with the oxidant electrode, which is formed of a conductive member and is in contact with the oxidant. An oxidant electrode side current collector having a plurality of guide grooves for flowing through,
A plurality of unit cells provided with an internal manifold mechanism for distributing and supplying a reactive gas to each of the guide grooves of the fuel electrode side current collector and the oxidant electrode side current collector are stacked, and each unit cell is stacked. A cooling plate is inserted into the cooling plate, and a part of the cooling water flowing through the cooling plate is passed through the humidifying water permeation body formed of a porous body, the fuel electrode side current collector, and the fuel electrode through the polymer. In a polymer electrolyte fuel cell adapted to be supplied to an electrolyte membrane, the fuel electrode side current collector is formed of a hydrophilic conductive porous body, and the humidification water permeation body is a water repellent conductive porous body. It is characterized by being formed by.

The humidified water permeation body may be formed by impregnating a hydrophilic conductive porous body with a water-repellent resin, or a conductive body having a plurality of fine pores having a diameter of 1 mm or less. It may be formed by a water-repellent treatment applied to a thin sheet having excellent properties. When a plurality of unit cells are stacked to form a stack, the humidifying water permeation body located in the lower part in the vertical direction may have a smaller arrangement density of the fine holes.

In order to achieve the above object, the third aspect of the present invention
In the invention of (1), a gas diffusion electrode composed of a fuel electrode and an oxidizer electrode having a smaller area than the polymer electrolyte membrane is arranged on both sides of the polymer electrolyte membrane, and packing is provided on the outer peripheral portion of the gas diffusion electrode. In a polymer electrolyte fuel cell in which gas sealing is performed by packing, the packing is formed of a sheet having elasticity smaller than that of the gas diffusion electrode, and is a convex type having a height exceeding the gas diffusion electrode. It is characterized in that a sealing lip is integrally provided.

When the packing is provided with holes for supplying and discharging fuel gas, oxidant gas, and cooling water, convex sealing lips are also provided around these holes. preferable. In addition, a convex inner sealing lip and an outer sealing lip are provided on the inner edge and the outer edge of the packing so as to go around the edges, respectively, and are formed between the inner and outer sealing lips after the battery is assembled. An inert gas may be formed so that the space can be injected.

[0022]

In the first aspect of the invention, the separator plate, the current collector outer frame adhered and fixed to at least one surface of the separator plate, and the conductive adhesive placed on the separator plate and placed on the separator plate. The current collector fixed with, the inner manifold element disposed between the current collector and the outer frame of the current collector and fixedly adhered to the separator plate, and the surface on which the guide groove of the current collector is formed. The contact resistance and the thickness of the separator unit, which has an opening facing the outside and has a region covering the internal manifold element, and a manifold cover that is adhesively fixed to the current collector outer frame, are incorporated. It can be managed so that it falls within a predetermined width before the assembly, and it becomes easy to assemble a plurality of stacks having substantially the same electric constants, which contributes to the improvement of the performance of the entire system. In addition, since the structure in which the separator unit is incorporated is adopted, the number of parts at the time of assembly can be substantially reduced, which can contribute to facilitation of assembly.

In the second aspect of the invention, since the fuel electrode side current collector is formed of a hydrophilic porous body and the humidification water permeation body is formed of a water repellent porous body, the pressure of the cooling water is the fuel. When the pressure is higher than the pressure of the gas flow by a predetermined amount or more, the amount of water determined by the pressure difference, the thickness of the humidifying water permeation body, the porosity, the average pore diameter, and the hydrophilicity is passed through the humidification water permeation body to the anode side current collector, That is, it can be supplied to the polymer electrolyte membrane. Therefore, by setting the pressure difference, the entire cell can be humidified when needed,
Further, the supply of water can be stopped when humidification is not required, such as when the battery is stopped or when it is sufficiently humidified by the water generated by the battery reaction, so that the system integrity can be improved. In this way, the required amount of humidification can be performed when necessary, so that the fuel electrode is not blocked by the excess water, which contributes to the improvement of the cell performance.

In the third aspect of the invention, a packing formed of a sheet having elasticity smaller than that of the gas diffusion electrode is arranged on the outer peripheral portion of the gas diffusion electrode, and a convex seal having a height exceeding the gas diffusion electrode is provided in the packing. Since the use lip is integrally provided, the difference in thickness between the gas diffusion electrode and the packing can be absorbed by the sealing lip, and thus the gas diffusion electrode and the current collector can be brought into good contact with each other. Therefore, it can contribute to the improvement of battery performance. Moreover, since the pressure receiving area in the packing can be reduced, the tightening force of the stack can be reduced.

[0025]

Embodiments will be described below with reference to the drawings. FIG. 1 shows an exploded perspective view of a polymer electrolyte fuel cell according to a first embodiment of the present invention.

This solid polymer fuel cell is composed of a single cell 21.
Are formed in a laminated structure in which a plurality of layers are laminated with the separator plates 22a and 22b and the humidifying water permeable plate 23 formed of a conductive porous material interposed therebetween.

The unit cell 21 is composed of a polymer electrolyte membrane 24 formed of a material similar to a known one, and a conductive porous material having an area smaller than that of the polymer electrolyte membrane 24. Fuel electrode 25 placed in contact with the lower surface in the figure
Similarly, an oxidizer electrode 26 formed of a conductive porous material having an area smaller than that of the polymer electrolyte membrane 24 and arranged in contact with the upper surface of the polymer electrolyte membrane 24 in the figure, and a seal having substantially the same thickness as the fuel electrode 25. And a sealing packing 27 formed of a material and arranged on the outer peripheral portion of the fuel electrode 25, and a sealing member formed of a seal material having substantially the same thickness as the oxidant electrode 26 and arranged on the outer peripheral portion of the oxidant electrode 26. And a part of the double-sided separator unit 29 having a function of supplying an oxidant gas to the oxidant electrode 26, a function of supplying water to the humidifying water permeable plate 23, and a current collecting function, and a fuel to the fuel electrode 25. It is composed of a part of the single-sided separator unit 30 having a gas supply function and a current collecting function.

As shown in FIGS. 2 and 4, the double-sided separator unit 29 includes the above-described dense separator plate 22a made of carbon, and a dense separator fixed on both surfaces of the separator plate 22a with, for example, an epoxy adhesive. Current collector outer frames 31 and 32 made of carbon, and these current collector outer frames 3
1 and 32 and collectors 33 and 34 fixed to the separator plate 22a with a conductive adhesive containing carbon, and the collectors 33 and 34 formed integrally with the collectors Internal manifold elements 35, 36, 37, 38 arranged in the frames 31, 32 and integrally fixed to the separator plate 22a with the conductive adhesive.
And openings 39 and 40 for exposing the current collectors 33 and 34 to the outside
With internal manifold elements 35, 36, 3
Current collector outer frame 3 with regions 41 and 42 covering 7, 38
1 and 32, and carbon manifold covers 43 and 44 fixed with an epoxy adhesive.

As shown in FIG. 4, a guide groove 4 for guiding the fluid is formed on the surface of the current collectors 33, 34 facing the outside from the openings 39, 40 of the manifold covers 43, 44.
5, 46 are formed in parallel. The internal manifold elements 35, 36, 37, 38 are mainly formed of elements having a plurality of grooves 47, 48 communicating with the above-mentioned guide grooves 45, 46.

Here, a manifold cover is provided between the surfaces of the current collectors 33 and 34 on which the guide grooves 45 and 46 are formed and the internal manifold elements 35, 36, 37 and 38 adjacent to both sides of the surfaces. A step corresponding to the thickness of 43, 44 is formed, and the presence of the step causes the guide grooves 45, 4 in the current collectors 33, 34 to be present as shown in FIG.
6 surface and manifold covers 43, 44
Is flush with the surface of.

Both sides of the double-sided separator unit 29,
On both sides of the single-sided separator unit 30, both sides of the polymer electrolyte membrane 24, and both sides of the packings 27 and 28,
As shown in FIGS. 1 and 4, holes 50 and 51 for supplying / discharging the fuel gas, holes 52 and 53 for supplying / discharging the cooling water, and supplying / discharging the oxidant gas. The holes 54 and 55 are provided so as to communicate with each other in the stacking direction.

The internal manifold elements 35 and 36 in the double-sided separator unit 29 communicate with the holes 52 and 53 for supplying / discharging cooling water, and the internal manifold elements 37 and 38 supply / discharging oxidant gas. To the holes 54 and 55.

As shown in FIG. 3, the single-sided separator unit 30 includes a separator plate 22b having a porous carbon portion 60 and a porous carbon member fixed to one surface of the separator plate 22b with, for example, an epoxy adhesive. Current collector outer frame 61, a current collector 62 arranged in the current collector outer frame 61 and fixed to the separator plate 22b with a conductive adhesive containing carbon, and the current collector 62 integrated with the current collector 62. Inner manifold elements 63 and 64 formed on the outer surface of the current collector outer frame 61 and integrally fixed to the separator plate 22b by the conductive adhesive, and an opening for exposing the current collector 62 to the outside. Manifold made of carbon fixed to the outer frame 61 of the current collector with an epoxy adhesive and having a region 66 that covers the inner manifold elements 63 and 64. And a cover 67.

That is, the single-sided separator unit 30
Is the same as one side of the above-mentioned double-sided separator unit 29 with the separator plate 22a as a boundary, except that the part of the separator plate 22b excluding the peripheral portion and the collector 62 are made of porous carbon. It is configured. However, the internal manifold elements 63 and 64 of the single-sided separator unit 30 communicate with the holes 50 and 51 for supplying / discharging the fuel gas.

A plurality of the unit cells 21 having the above-described structure are stacked with the humidifying water permeable plate 23 interposed therebetween to form a fuel cell stack 70.
Is configured. Then, the conductive end plates 7 are formed on both end faces of the fuel cell stack 70 located in the stacking direction.
1, 72 are applied, and these end plates 7
Clamping plates (not shown) wider than the end plates are applied to the outer surfaces of 1 and 72, and both clamping plates are clamped with an insulating rod in the stacking direction under the condition that a spring is interposed at the peripheral edge of these clamping plates. Has become.

On the upper surface of the end plate 71, the fuel supply pipe 73 and the fuel discharge pipe 74 for supplying / discharging the fuel gas through the above-mentioned holes 50 and 51, and the above-mentioned holes 52 and 53 are provided. The cooling water supply pipe 75 and the cooling water discharge pipe 76 for supplying / discharging the cooling water via the above-mentioned hole 5
An oxidant gas supply pipe 77 and an oxidant gas discharge pipe 78 for supplying / discharging the oxidant gas through 4, 55 are provided in a relationship leading to the corresponding holes.

With such a structure, the fuel supply pipe 73
The fuel gas supplied via each of the single cells 21 flows into each groove of the current collector 62 via the internal manifold element 63 of the single-sided separator unit 30. Then, a part thereof is diffused to the fuel electrode 25 and used for power generation, and the rest flows to the hole 51 through the internal manifold element 64 and then to the fuel discharge pipe 74. Also, the oxidant supply pipe 77
The oxidant gas supplied via the gas flows to each groove 46 of the current collector 34 in each single cell 21 via the internal manifold element 37 in the double-sided separator unit 29.
Then, a part of them diffuses into the oxidant electrode 26 and is used for power generation,
The remainder flows through the inner manifold element 38 to the holes 55 and then to the oxidant discharge pipe 78. On the other hand, the cooling water supplied via the cooling water supply pipe 75 flows into each groove 45 of the current collector 33 in each single cell 21 via the internal manifold element 35 in the double-sided separator unit 29. Then, a part of them permeates the humidifying water permeable plate 23, the porous carbon portion 60 of the separator plate 22b of the single-sided separator unit 30, the current collector 62, and the fuel electrode 25, respectively, and is used for humidifying the polymer electrolyte membrane 24. , The rest flows through the internal manifold element 36 to the holes 53 and then to the cooling water discharge pipe 76.

As described above, the function of the battery is exerted by supplying the fuel gas, the oxidant gas and the cooling water.
In this case, since the double-sided separator unit 29 and the single-sided separator unit 30 having the above-described structure integrated by the adhesive are incorporated, the contact resistance and the thickness of these units can be accurately measured before assembling. Can be managed. As a result, it becomes easy to assemble a plurality of stacks having substantially the same electric constants, so that the performance of the entire system can be improved.

A cell was assembled using these separator units, and the voltage drop due to the contact resistance was measured and found to be 30 mV at a current density of 0.4 A / cm ² . For comparison, the voltage drop of the cell assembled by sequentially stacking each component as in the conventional configuration was measured, and the same current density was obtained.
It was 70 mV. Thus, it was confirmed that the battery performance can be improved by using the separator unit.

Further, if the construction in which the separator unit is incorporated is adopted, the number of parts can be substantially reduced at the time of assembling, so that the assembling can be facilitated.
Although the current collector and the manifold element are integrally formed in the above-described embodiment, the current collector 80 and the manifold elements 81 and 82 are separately provided as shown in FIG. The formed product may be incorporated into the separator unit. Further, in the above-described embodiment, the flow direction of the fuel gas flowing through the groove formed in the current collector on the fuel electrode side and the flow direction of the oxidant gas flowing through the groove formed in the current collector on the oxidant electrode side Although and are set to be a parallel flow, they may be set to a counter flow or a cross flow.

Further, when mechanical strength can be secured, as shown in FIG. 6, the manifold element is omitted, and a semicircular shape which functions as a manifold on both sides of the current collector 83.
You may use the single-sided separator unit 85 which provided the cavity 84 of triangular shape. Of course, a double-sided separator unit can also be constructed.

In the example shown in FIG. 6, a carbon separator element 85 having a shape in which a separator plate and a current collector outer frame are integrated is used. Also, the manifold cover 86
Has a opening 87 facing the current collector 83 in the center, and has a thickness such that the surface thereof is exactly flush with the grooved surface of the current collector 83 when this is bonded and fixed to the separator element 85. Is used. Incidentally, in FIG. 6, 88,
Reference numeral 89 indicates a hole for passing the fuel gas, and 90, 9
Reference numeral 1 denotes a hole for passing an oxidant gas, and a hole for guiding cooling water is omitted.

Next, a polymer electrolyte fuel cell according to a second embodiment of the present invention will be described with reference to FIG.
As described above, in order to operate the polymer electrolyte fuel cell well, it is necessary to uniformly humidify the polymer electrolyte membrane forming the electrolyte layer. At the same time, it is desirable that the supply of humidifying water can be stopped when the system is stopped or when the polymer electrolyte membrane is sufficiently humidified by the water produced by the battery reaction.

In this embodiment, such a demand can be realized with a simple structure, and only a single cell is shown in FIG. In the figure, reference numeral 100 indicates a polymer electrolyte membrane formed of a material similar to a known one. A fuel electrode 101 formed of a conductive porous material having an area smaller than that of the polymer electrolyte membrane on both sides of the polymer electrolyte membrane 100.
And the oxidant electrode 102 are arranged in contact with each other. Fuel pole 10
Packings 103 and 104 for gas sealing, which are formed of a sealing material having substantially the same thickness as each electrode, are arranged on the outer peripheral portions of the electrode 1 and the oxidant electrode 102.

On the lower surface side of the fuel electrode 101 in the figure, the fuel electrode 1
The fuel electrode side current collecting plate 105 that exhibits the function of supplying the fuel gas to the fuel cell 01 and the current collecting function is arranged in contact. On the contact surface of the fuel electrode side current collector plate 105 with the fuel electrode 101,
A plurality of guide grooves 106 for allowing the fuel gas to flow therethrough are formed. Similarly, on the upper surface side of the oxidizer electrode 102 in the figure,
An oxidant electrode side current collector plate 107, which has a function of supplying an oxidant gas to the oxidant electrode 102 and a current collecting function, is arranged in contact with each other. The oxidant electrode 10 in the oxidant electrode side current collector plate 107
A plurality of guide grooves 108 for allowing the oxidant gas to flow therethrough are also formed on the contact surface with 2.

The fuel electrode side current collector plate 105 is a hydrophilic carbon porous plate having a porosity of 70% and an average pore diameter of 40 μm.
6 is provided. Further, the oxidizer electrode side current collector plate 107 is formed of a carbon plate provided with a guide groove 108.

On the other hand, a humidifying water permeable plate 109 is arranged in contact with the lower surface of the fuel electrode side current collecting plate 105 in the drawing, and a cooling plate 110 is arranged in contact with the lower surface of the humidifying water permeable plate 109 in the drawing. There is.

The humidifying water permeable plate 109 is formed by applying water repellent treatment to a porous thin plate of hydrophilic carbon having a porosity of 40% and an average pore diameter of 5 μm. That is, a porous thin plate of hydrophilic carbon is immersed in a suspension containing fine particles of fluorocarbon and then fired at a temperature of 300 ° C. or higher, whereby the surface of pores is coated with fluorocarbon to make it water repellent. At this time, water droplets are dropped on the surface of the humidifying water transmission plate 109, and after confirming that the contact angle is 90 ° or more, both surfaces are polished to have conductivity.

The cooling plate 110 is formed of a carbon plate provided with a plurality of guide grooves 111 constituting a cooling water flow path, and the surface provided with the guide grooves 111 is the lower surface of the humidifying water permeable plate 109 in the figure. It has been attached to.

A fuel cell stack is formed by stacking a plurality of unit cells thus configured. The guide groove 106 provided on the fuel electrode side current collector plate 105, the guide groove 108 provided on the oxidant electrode side current collector plate 107, and the cooling plate 110.
The guide groove 111 provided in is connected to the fuel gas supply system, the oxidant gas supply system, and the cooling water supply system through an internal manifold mechanism similar to that of a known polymer electrolyte fuel cell.

As described above, the fuel electrode side current collector plate 105 is formed of the hydrophilic conductive porous material, and the fuel electrode side current collector plate 1 is formed.
The humidifying water permeable plate 109 provided in contact with 05 is made of a water-repellent conductive porous material. Therefore,
The amount of humidifying water that passes through the humidifying water transmission plate 109 and the fuel electrode side current collecting plate 105 and moves to the fuel electrode 101, that is, the polymer electrolyte membrane 100 is determined by the pressure of the cooling water flowing in the groove 111 and the fuel flowing in the groove 106. It is greatly affected by the pressure difference from the gas pressure. Therefore, the amount of humidifying water can be freely adjusted by controlling the differential pressure.

That is, the unit cell of this embodiment shown in FIG. 7 and a conventional unit cell using a hydrophilic humidifying water permeable plate were prepared, and the grooves 106 and 111 were filled with fuel gas and cooling water at normal pressure. When left for several days, the conventional single cell partially leaked the cooling water and clogged the groove 106 which is the fuel flow path, whereas the single cell of the present embodiment almost leaked the cooling water. It was confirmed that not.

When the pressurized fuel gas and cooling water were supplied and the pressure of the cooling water was changed to examine the change in the amount of water permeation, that is, the amount of humidification, the results shown in FIG. 8 were obtained. In FIG. 8, A shows the data of the single cell of this embodiment, and B shows the data of the conventional single cell.

In the case of the conventional single cell using the hydrophilic humidifying water permeable plate, since water is supplied by the capillary phenomenon, a part of the cooling water is generated even when the cooling water and the fuel gas have the same pressure. It is supplied to the polymer electrolyte membrane 100. On the other hand, in the single cell of this example, due to the water repellency of the pore surface,
When the differential pressure between the cooling water and the fuel gas is smaller than a predetermined value (10 kPa), part of the cooling water is not supplied to the polymer electrolyte membrane 100. Then, when the differential pressure exceeds a predetermined value, a part of the cooling water is supplied to the polymer electrolyte membrane 100, and the supply amount thereof increases as the differential pressure increases. In the single cell of this example, the polymer electrolyte membrane 100 could be sufficiently humidified at the level of the differential pressure of 10 kPa.

As described above, the water-repellent humidifying water transmitting plate 109 is used.
Since the pressure of the cooling water is equal to the pressure of the fuel gas, or when the pressure of the cooling water is low, the supply of the humidifying water can be stopped. By setting the difference, the polymer electrolyte membrane 100 can be satisfactorily humidified. In addition,
The determination as to whether or not the humidifying water is being supplied without excess or deficiency can be easily known by a change in the supply pressure of the fuel gas or the like.
Therefore, it is possible to prevent the fuel gas flow path from being blocked by the surplus humidifying water and from deteriorating the cell performance.

The unit cell shown in FIG. 7 is laminated to form a laminated battery, and the fuel flow and cooling water pressure distribution of each cell when cooling water is supplied at a pressure higher than the fuel flow by 100 kPa. Upon examination, the results shown in FIG. 9 were obtained. Also,
When the distribution of the amount of humidification of each cell at that time was examined, it was shown in FIG.
The result shown in 0 was obtained. These figures also show the characteristics of a laminated battery incorporating a conventional single cell adopting a humidification method by a capillary phenomenon.

In the laminated battery, due to pressure loss such as branching loss and merging loss, the cooling water and the fuel gas have different pressures in each single cell. In the conventional humidification method, an appropriate amount of humidification water can be supplied to a cell in which the fuel gas pressure and the cooling water pressure are the same, but the cells in which the cooling water pressure and the fuel gas pressure are different, especially the cooling water In a cell with a high pressure, water is excessively supplied, and a significant difference in humidification amount occurs between cells. On the other hand, in the laminated battery in which the single cell of the present embodiment is incorporated, since the humidifying water is supplied by applying the differential pressure, it is possible to reduce the variation in the pressure difference between the cells and the variation in the humidification amount. Can be made smaller.

Further, an experiment was conducted by incorporating a humidifying water permeable plate (having a water repellent treatment) having a small porosity or a small average pore diameter into a cell having a large pressure difference between the cooling water and the fuel gas.
In this experiment, No. 1 having the smallest pressure difference. A humidifying water permeation plate with a porosity of 40% was incorporated into cell No. 1, and a humidifying water permeation plate with a porosity that decreased by 1% as the cell number increased by 1 was incorporated. And 100k from fuel gas flow
When the distribution of the amount of humidification of each cell when the cooling water was supplied at a high Pa pressure was investigated, the results shown in FIG. 10 were obtained. As can be seen from this result, by selecting the porosity of the humidifying water permeation plate according to the pressure difference, the difference in the amount of humidification caused by the pressure difference in each unit cell can be made smaller, and each unit cell can be made uniform. Can be sufficiently humidified.

In order to easily generate a pressure difference between the cooling water and the fuel gas flow, the humidifying water permeable plate 109 should have a porosity or average pore size smaller than that of the fuel electrode side current collecting plate 105. Better to use.

Further, the porosity is 45% or more, and the average pore diameter is 10 μm.
In the above porous body, it is difficult to provide a pressure difference of 10 kPa or more at a thickness of 1 mm, and thus a porosity and an average pore diameter smaller than that are desirable.

The porosity and the average pore diameter can be obtained by selecting the material of the conductive porous material that constitutes the humidifying water permeable plate, but can also be realized by the water repellent treatment. For example, as a base material for a water-repellent humidified water permeable plate, a porosity of 70%
An example of using a hydrophilic carbon porous thin plate having an average pore diameter of 40 μm will be described.

First, in the above carbon porous thin plate, the ratio W of the impregnation capacity to the pore volume is 43%, 50% and 57%, that is, the porosity after impregnation is 49%, 35% and 30%. Impregnate. Drop water drops on the surface and
After confirming that it is 90 ° or more, both sides are polished to have conductivity.

FIG. 11 shows the humidification amount F when a differential pressure of 100 kPa is applied to the three water-repellent humidifying water transmitting plates thus manufactured. The higher the impregnation ratio, the smaller the amount of humidification. Therefore, by changing W, the porosity is 30% in 1% increments.
When a total of 10 humidifying water permeation plates of 40% were manufactured and used in the laminated battery, each cell could be uniformly humidified as in the result shown by A in FIG.

As described above, by impregnating an appropriate amount of fluorocarbon, it becomes possible to manufacture a water-repellent humidifying water permeable plate, and by varying the impregnation amount, a predetermined pressure difference can be obtained. The amount of humidification can be adjusted. Since the porosity and average pore diameter can be adjusted by the amount of impregnation, a conductive porous body having a porosity of 70% or more or an average pore diameter of 40 μm or more can be used, but the porosity after impregnation is
It is desirable that it is less than 45% and the average pore size is less than 10 μm.

Further, in each of the above-mentioned examples, the humidifying water permeable plate formed by subjecting the conductive porous material to the water repellent treatment is used. However, as shown in FIG. 12, a fine carbon thin plate has a diameter of 1 mm. It is also possible to use a humidifying water transmission plate 109a formed by subjecting a large number of the following fine holes 112 to a water repellent treatment.

For example, 60,9 is formed on a dense sheet of carbon.
Micro holes 112 of 0,120 μm were formed by laser processing. Then, the same water repellent treatment as the above example was applied. The amount of humidification per one fine hole when a differential pressure of 100 kPa was applied to the three water-repellent humidified water permeation plates thus manufactured was examined, and the results shown in FIG. 13 were obtained. As can be seen from this figure, the amount of humidification decreases as the hole diameter decreases.

As described above, by using the humidifying water permeable plate 109a formed by subjecting the conductive dense thin plate with the fine holes to the water repellent treatment, and changing the fine hole diameter for each single cell, It is possible to adjust the humidification amount at a predetermined pressure difference. Furthermore, by changing the number of fine holes per unit area for each single cell or for every several single cells, the amount of humidification at a predetermined pressure difference can be precisely controlled.

An example in which the number of fine holes per unit area is changed will be described with reference to FIG. In this example, the fuel cell stack 113 is configured by stacking a plurality of single cells so that the water-repellent humidifying water permeable plate incorporated in each single cell is orthogonal to the direction of gravity. Then, the fuel cell stack 113 is divided into three regions 114, 115, and 116 in the direction of gravity, and the number of fine holes of the humidifying water permeation plate is changed for each region. That is, 90 μm fine holes are formed in the region 114 at 3 cm / cm ^2.
The region 115, the region 115 has two regions, and the region 116 has one region.

As described above, if the number of fine holes is increased in the upper part in the direction of gravity and the number of fine holes is decreased in the lower part,
It is possible to prevent each unit cell located in the lower part from being excessively humidified by the influence of gravity, and it is possible to uniformly humidify each region.

Next, referring to FIG. 15, the third embodiment of the present invention will be described.
The polymer electrolyte fuel cell according to the example will be described. As described above, in the polymer electrolyte fuel cell, packing is arranged around the fuel electrode and the oxidant electrode, and the packing seals the fuel gas, the oxidant gas, and the cooling water. However, if there is a difference between the thickness of the packing and the thickness of the electrode, the contact resistance between the fuel electrode or the oxidizer electrode and the current collector may increase, or the sealing may be defective. Further, in the case where the packing is provided with the holes for supplying / discharging the fuel gas, the oxidant gas and the cooling water, the packing area becomes large, and as a result, a large tightening force is required to form the stack. .

In this embodiment, such a problem can be solved by a simple structure, and FIG. 15 shows only a main part of a single cell. In the figure, reference numeral 120 denotes a polymer electrolyte membrane formed of a known material. On both sides of the polymer electrolyte membrane 120, a thickness formed of a conductive porous material having an area smaller than that of the polymer electrolyte membrane
A 400 μm fuel electrode 121 and an oxidizer electrode 122 are arranged in contact with each other.

On the outer peripheral portions of the fuel electrode 121 and the oxidant electrode 122, packing 123, 1 for gas sealing formed of an elastic sheet having a thickness of 200 μm, for example, a rubber sheet.
24 are arranged.

As shown in FIG. 16 as a representative of only the packing 124, the packings 123 and 124 are located on the side opposite to the surface in contact with the polymer electrolyte membrane 120 and close to the oxidizer electrode 122. A convex endless lip 125 for sealing having a height of 300 μm and a width of 1 mm is integrally provided so as to surround the oxidizer electrode 122. Also packing 1
23 and 124, holes 126 and 127 for supplying / discharging fuel gas, holes 128 and 129 for supplying / discharging oxidant gas, and holes 130 for supplying / discharging cooling water. 131 is provided, and a convex endless lip 132 for sealing having a height of 300 μm and a width of 1 mm is also provided around these holes.
~ 137 are integrally projected.

On the lower surface side of the fuel electrode 121 in the drawing, the fuel electrode 1
Fuel electrode side current collector plate 1 formed of a hydrophilic carbon porous plate that exhibits a function of supplying fuel gas to 21 and a current collector function
38 is arranged in contact. This fuel electrode side current collector 138
A plurality of guide grooves 139 for allowing a fuel gas to flow therethrough are formed on the contact surface with the fuel electrode 121.

Similarly, on the upper surface side of the oxidant electrode 122 in the figure, the oxidant electrode side current collector formed of a carbon plate having a function of supplying the oxidant gas to the oxidant electrode 122 and a current collecting function is shown. A plate 140 is arranged in contact. On the contact surface of the oxidant electrode side current collector 140 with the oxidant electrode 122, a plurality of guide grooves 141 for allowing the oxidant gas to flow therethrough are also formed.

The main part of the single cell thus constructed is
A plurality of laminated humidifying water permeation plates and cooling water distribution plates (not shown) are arranged on the side of the fuel electrode side current collector 138, and the laminated body is clamped in the stacking direction by clamping means (not shown) to form a fuel cell stack. It

The fuel electrode side current collector plate 138 and the oxidant electrode side current collector plate 140 are provided with holes 126 and 127 for supplying / discharging the fuel gas and supplying / discharging the oxidant gas. Holes 128 and 129 are provided, and holes 130 and 131 provided for supplying / discharging cooling water are provided, respectively.

As described above, the packings 123 and 124 having elasticity smaller than those of the electrodes are arranged on the outer peripheral portions of the fuel electrode 121 and the oxidant electrode 122, and the portions surrounding the electrodes of these packings 123 and 124 and Convex endless lip 12 for sealing, having a height exceeding each electrode around a hole provided for passing each fluid.
5,132-137 are integrally provided.

Therefore, the fuel electrode 121 and the oxidant electrode 12
2 and the thickness of the packing 123, 124 can be absorbed by the sealing endless lips 125, 132 to 137, whereby the fuel electrode 121 and the fuel electrode side current collecting plate 13 are absorbed.
8 and the oxidant electrode 122 and the oxidant electrode side current collector 140 can be brought into good contact with each other, which can contribute to improvement of battery performance. Further, the tightening force when forming the stack is applied only to the sealing endless lips 125, 132 to 137. Therefore, the pressure receiving area of the packing 123, 124 can be reduced, and a good seal can be realized with the stack tightening force reduced.

In order to confirm the effects described above, the unit cell of this example and a conventional unit cell using a flat rubber packing having a thickness of 500 μm and a width of 20 mm were prepared and clamped with a metal spring. Then, the fuel gas and the oxidant gas pressurized to 0.3 MPa and 0.2 MPa, respectively, were supplied and left for 1 hour. This test was performed by changing the tightening force, and the tightening force at which the pressures of the fuel gas and the oxidant gas after being left unchanged were examined. As a result, the tightening force of the single cell of this example is
It was 2800-2900 (kgf). On the other hand, the tightening force of the conventional single cell was 7300 to 8200 (kgf).

As described above, in the single cell of this embodiment, the pressure receiving area of the seal portion can be reduced, so that the tightening force required for sealing can be reduced to 38% as compared with the conventional unit cell.

Next, under the above tightening force, the contact resistance between the fuel electrode 121 and the fuel electrode side current collecting plate 138 was measured for the unit cell of this embodiment and the conventional unit cell. As a result, the contact resistance of the single cell of this example was 0.11 to 0.12 (
Ωcm ² ). On the other hand, the contact resistance of the conventional single cell was 0.25 to 0.33 (Ωcm ² ).

As described above, in the unit cell of this embodiment, the difference in thickness between the electrode and the packing is determined by the endless lip 12 for sealing.
Since it can be easily absorbed by 5, 132 to 137, the contact resistance can be reduced as compared with the conventional single cell.

As can be seen from the above example, the packing 12
The thickness of the sheets of 3,124 is preferably thinner than the thickness of the fuel electrode 121 and the oxidant electrode 122, and the total thickness of the sheets of the packing 123,124 and the thickness of the endless lip for sealing is the fuel electrode 121. And the thickness of the oxidant electrode 122 is preferably larger than that.

Further, in the above embodiment, the packing 12
Although the sealing endless lip is provided on one side of 3,124, the sealing endless lip may be provided on both sides. Also in this case, the thickness of the packing sheet is preferably thinner than the thicknesses of the fuel electrode 121 and the oxidant electrode 122. Further, the sum of the thickness of the packing sheet and the thickness of both sides of the lip is preferably larger than the thicknesses of the fuel electrode 121 and the oxidant electrode 122.

In the above embodiment, the packing 1
A convex endless lip for sealing 125, 132 to 137 having a height exceeding each electrode around a portion surrounding each electrode of 23, 124 and a hole provided for passing each fluid.
In addition to this structure, as shown in FIG. 18, at least one convex endless lip 142 for sealing which surrounds the peripheral edge of the packing 123a (124b) is provided in addition to this configuration. At the same time, a hole 144 for communicating the space 143 existing between the endless lips 125 and 142 for sealing to the outside may be provided so that pressurized inert gas such as nitrogen can be injected into the space 143 through the hole 144 after assembly. .

With this configuration, fuel gas is supplied /
Holes 126 and 127 provided for discharge, supply of oxidant gas /
Supply of holes 128 and 129 and cooling water for discharge /
Since it is possible to press a portion outside the sealing endless lips 132 to 137 provided around the holes 130 and 131 to be discharged, these sealing endless lips 1
The pressure difference between the inner and outer surfaces of 32 to 137 can be reduced, and the pressurized supply gas and cooling water can be more reliably prevented from mixing with each other.

[0088]

As described above, according to the present invention,
Despite the simple structure, it can contribute to the improvement of battery performance.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a polymer electrolyte fuel cell according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a double-sided separator unit incorporated in the battery.

FIG. 3 is a vertical cross-sectional view of a single-sided separator unit incorporated in the battery.

FIG. 4 is an exploded perspective view of a double-sided separator unit incorporated in the battery.

FIG. 5 is a perspective view showing a modified example of a current collector and a manifold element incorporated in the separator unit.

FIG. 6 is an exploded perspective view showing a modified example of the separator unit.

FIG. 7 is a vertical cross-sectional view of a single cell in a polymer electrolyte fuel cell according to a second embodiment of the present invention.

FIG. 8 is a diagram showing humidification characteristics of the same single cell in comparison with characteristics of a conventional single cell.

FIG. 9 is a diagram showing characteristics of a laminated battery incorporating the same single cell in comparison with characteristics of a conventional laminated battery.

FIG. 10 is a view showing characteristics of a laminated battery incorporating the same single cell in comparison with characteristics of a conventional laminated battery.

FIG. 11 is a diagram showing the relationship between the porosity of a humidifying water-permeable plate and humidifying characteristics.

FIG. 12 is a vertical cross-sectional view for explaining a modified example of the humidifying water transmission plate.

FIG. 13 is a diagram showing a relationship between a diameter of micropores provided in the humidifying water transmission plate and a humidification amount.

FIG. 14 is a view for explaining an example of a laminated battery incorporating the humidifying water transmission plate.

FIG. 15 is an exploded vertical sectional view of a single cell in a polymer electrolyte fuel cell according to a third embodiment of the present invention.

FIG. 16 is a plan view of packing incorporated in the same single cell.

FIG. 17 is an exploded vertical sectional view showing the same single cell cut along a line orthogonal to the paper surface of FIG.

FIG. 18 is a plan view for explaining a modification of packing.

FIG. 19 is an exploded perspective view of a typical conventional polymer electrolyte fuel cell.

[Explanation of symbols]

21 ... Single cell 22a, 22b ... Separator plate 23, 109, 109a ... Humidifying water permeable plate 24, 100, 120 ... Polymer electrolyte membrane 25, 101, 121 ... Fuel electrode 26, 102, 122 ... Oxidizing agent electrode having gas diffusion function 27, 28, 103, 104, 123, 124 ... Packing 29 ... Double-sided separator unit 30 ... Single-sided separator unit 31, 32, 61 ... Current collector outer frame 33, 34, 62, 80, 83 ... Current collectors 35, 36, 37, 38, 63, 64, 81, 82 ... Manifold elements 39, 40, 65, 87 ... Openings 43, 44, 67, 86 ... Manifold covers 45, 46, 47, 48 ... Guide groove 70 ... Fuel cell stack 50-55, 88-91, 126-131 ... Holes 125, 132 that form an internal manifold 137,142 ... sealing endless lip 144 ... inert gas the necessity of hole

Front page continuation (72) Inventor Kenji Murata 1 Komukai Toshiba-cho, Kawasaki-shi, Kanagawa Kanagawa Prefecture Inside the Corporate Research and Development Center, Toshiba Corporation

Claims (9)

[Claims] 1. A polymer electrolyte membrane, a pair of gas diffusion electrodes provided in contact with both surfaces of the polymer electrolyte membrane, and a gas diffusion electrode provided in contact with these gas diffusion electrodes. A pair of current collectors having a plurality of guide grooves for allowing the reactive gas to flow therethrough, and an internal manifold mechanism for distributing the reactive gas to the guide grooves of the current collectors are provided. A unit cell, a solid polymer electrolyte fuel cell formed by stacking a plurality of conductive separator plates via a conductive separator plate, the separator plate, and a current collector outer frame adhesively fixed to at least one surface of the separator plate, The current collector, which is arranged in the outer frame of the current collector and fixed to the separator plate with a conductive adhesive, and the separator plate, which is arranged between the current collector and the outer frame of the current collector. Contact A fixed inner manifold element and an opening for exposing the surface of the current collector on which the guide groove is formed to the outside and a region for covering the inner manifold element are fixed to the outer frame of the current collector. A polymer electrolyte fuel cell comprising a separator unit including a manifold cover. 2. The separator plate, the current collector outer frame, the current collector, the internal manifold element, and the manifold cover, which constitute the separator unit, are each formed of carbon. Item 1. The polymer electrolyte fuel cell according to Item 1. 3. The polymer electrolyte fuel cell according to claim 1, wherein the current collector and the manifold element are integrally formed. 4. A polymer electrolyte membrane, a porous fuel electrode provided in contact with one surface of the polymer electrolyte membrane, and a porous fuel electrode provided in contact with the other surface of the polymer electrolyte membrane. A porous oxidizer electrode and a plurality of guide grooves formed of an electrically conductive porous body are provided in contact with the fuel electrode and a plurality of guide grooves are provided on the contact surface with the fuel electrode for allowing fuel gas to flow therethrough. And a plurality of guide grooves for allowing an oxidant gas to flow through the contact surface with the oxidant electrode, which is formed of a conductive member and is in contact with the oxidant electrode. Unit cell including an oxidant electrode side current collector, and an internal manifold mechanism for distributing and supplying a reactive gas to the guide grooves of the fuel electrode side current collector and the oxidant electrode side current collector While stacking multiple, insert a cooling plate for each unit cell,
A part of the cooling water flowing through the cooling plate is supplied to the polymer electrolyte membrane through the humidifying water permeation body formed of a porous body, the fuel electrode side current collector and the fuel electrode. In the polymer electrolyte fuel cell described above, the fuel electrode side current collector is formed of a hydrophilic conductive porous body, and the humidification water permeation body is formed of a water repellent conductive porous body. A characteristic polymer electrolyte fuel cell. 5. The solid polymer fuel according to claim 4, wherein the humidifying water permeation body is formed of a hydrophilic conductive porous body impregnated with a water repellent resin. battery. 6. The moisturizing water permeation body is formed by applying a water-repellent treatment to a conductive and dense thin plate provided with a plurality of fine holes having a diameter of 1 mm or less. 4. The polymer electrolyte fuel cell according to item 4. 7. A gas diffusion electrode consisting of a fuel electrode and an oxidizer electrode having a smaller area than the polymer electrolyte membrane is arranged on both sides of the polymer electrolyte membrane, and packing is provided on the outer peripheral portion of the gas diffusion electrode. In a polymer electrolyte fuel cell in which gas sealing is performed by this packing, the packing is formed of a sheet having elasticity smaller than that of the gas diffusion electrode, and a protrusion having a height exceeding the gas diffusion electrode. A polymer electrolyte fuel cell, characterized in that a mold sealing lip is integrally provided. 8. The packing is provided with holes for supplying and discharging fuel gas, oxidant gas, and cooling water, and convex sealing lips are also provided around these holes. The polymer electrolyte fuel cell according to claim 7, wherein 9. The packing is provided with a convex inner sealing lip and an outer sealing lip that respectively make a turn along each of the inner edge portion and the outer edge portion of the packing. The solid polymer fuel cell according to claim 7 or 8, wherein an inert gas can be injected into a space formed between the inner and outer sealing lips.