JP2009043689A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell which can obtain a high output density by utilizing chimney effects and by taking in sufficient air in air passage. <P>SOLUTION: In a fuel cell 10, heat is generated by power generation in an MEA 13 and heated air by the heat rises in the air passage 31 and is exhausted out from an open port 31a on a top end, and negative pressure is generated in the air passage 31. Thus, a large amount of air is taken in the air passage 31 through an air introduction passage 32 connected to the air passage 31, and high output density can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly to a fuel cell in which sufficient air is taken into an air flow path and a high power density can be obtained using a chimney effect.

  A fuel cell is a device that converts chemical energy of a fuel gas into electrical energy by causing an electrochemical reaction between a fuel gas containing hydrogen and an oxidant gas containing oxygen such as air.

  Conventionally, two types of fuel cell configurations, a passive type and an active type, have been proposed. The passive type is a method of supplying air by a diffusion phenomenon without using a power mechanism such as a pump or a blower for supplying oxygen. On the other hand, the active type is a system that positively uses transport power to introduce the oxidant gas. Comparing the passive type and the active type, the former does not use a power mechanism for introducing air, so the system structure is simple and the power generation efficiency is high.

With reference to FIG. 5, the air supply in the conventional passive fuel cell 200 will be described. FIG. 5A is a diagram illustrating a conventional passive fuel cell 200, and FIG. 5B is a diagram schematically illustrating a configuration of an air supply unit of the passive fuel cell 200 illustrated in FIG. As shown in FIG. 5, in the conventional passive fuel cell 200, the pair of plates 202 and 203 that support the membrane-electrode assembly 201 is opened upward to the plate 202 on the oxidant electrode layer side. An air supply hole 205 is provided. Therefore, when air is consumed by power generation, air is taken into the air supply hole 205 by natural diffusion, and air is supplied to the membrane-electrode assembly 201 (see, for example, Patent Document 1).
JP 2006-221967 A

  However, the conventional passive fuel cell has a problem that sufficient air cannot be supplied and the output density is low. In particular, when a high load output is required, a larger amount of air is required, so that such a problem becomes remarkable.

  The present invention has been made to solve the above problems, and in particular, provides a fuel cell in which sufficient air is taken into the air flow path and high power density can be obtained by utilizing the chimney effect. The purpose is to do.

  To achieve this object, the fuel cell according to claim 1 has a membrane electrode assembly in which both sides of a solid polymer electrolyte are sandwiched between a fuel electrode layer comprising a reaction layer and a diffusion layer and an oxidant electrode layer. A fuel electrode layer side plate disposed on both sides of the membrane electrode assembly, in which a fuel flow path is formed, and an oxidant electrode layer side plate in which an air flow path is formed. The path is formed through the plate substantially perpendicularly to the surface of the oxidant electrode layer, and one opening is opened to the outside of the oxidant electrode layer side plate, and the other opening is the air. An air introduction path communicating with the vicinity of the oxidant electrode layer in the flow path is formed.

  The fuel cell according to claim 2 is characterized in that, in the fuel cell according to claim 1, the opening diameter of the air flow path is larger than the opening diameter of the air introduction path. .

  The fuel cell according to claim 3 is the fuel cell according to claim 1 or 2, wherein the air flow path has a distance in a direction substantially perpendicular to the surface of the oxidant electrode layer. It is configured to be at least twice the opening diameter.

  The fuel cell according to claim 4 is the fuel cell according to any one of claims 1 to 3, wherein the air introduction path has a distance from an opening opened to the outside to the air flow path. The air flow path is configured to be smaller than the distance of the air flow path in a direction substantially perpendicular to the surface of the layer.

  The fuel cell according to claim 5 is the fuel cell according to any one of claims 1 to 4, wherein the air flow path and the air introduction path are formed in a cylindrical shape.

  The fuel cell according to claim 6 is the fuel cell according to any one of claims 1 to 5, wherein the opening of the air introduction path is provided on an end surface of the oxidant electrode layer side plate.

  According to the fuel cell of the first aspect, there is an effect that sufficient air is taken into the air flow path by using the chimney effect and a high output density is obtained. That is, the air heated by the heat generated during power generation passes through the air flow path penetrating the oxidant electrode layer side plate and is discharged, so that a negative pressure is generated in the air flow path. Therefore, a large amount of air is taken into the air flow path through the air introduction path where one opening is opened to the outside and the other opening communicates with the oxidant electrode layer in the air flow path.

  According to the fuel cell of the second aspect, in addition to the effect achieved by the fuel cell of the first aspect, the air flow path is configured such that the opening diameter thereof is larger than the opening diameter of the air introduction path. Therefore, the air heated in the vicinity of the oxidant electrode layer side plate is efficiently exhausted from the opening of the air channel, and there is an effect that a large amount of air can be taken into the air channel. The “opening diameter” means the maximum length of line segments having both ends on the opening edge.

  According to the fuel cell of claim 3, in addition to the effect of the fuel cell of claim 1 or 2, the air flow path is a distance in a direction substantially perpendicular to the surface of the oxidant electrode layer, that is, air. Since the pipe length of the flow path is configured to be twice or more the opening diameter of the air flow path, there is an effect that air is taken in more efficiently. This is because the chimney effect is more effective as the pipe length of the chimney portion (corresponding to the air flow path) for exhausting air is longer.

  According to the fuel cell of claim 4, in addition to the effect of the fuel cell according to any one of claims 1 to 3, the air introduction path is a distance from the opening opened to the outside to the air flow path, that is, air Since the pipe length of the introduction path is configured to be smaller than the distance of the air flow path in the direction substantially perpendicular to the surface of the oxidant electrode layer, that is, the pipe length of the air flow path, the suction pressure Loss is reduced, and there is an effect that air is taken into the air flow path more efficiently.

  According to the fuel cell of the fifth aspect, in addition to the effect exhibited by the fuel cell according to any one of the first to fourth aspects, the air flow path and the air introduction path are configured in a cylindrical shape, so that the pressure loss is reduced. There is an effect that air is taken in more efficiently.

  According to the fuel cell of the sixth aspect, in addition to the effect exhibited by the fuel cell according to any one of the first to fifth aspects, the opening of the air introduction path is provided on the end surface of the oxidant electrode layer side plate. The distance between the opening of the air introduction path and the opening of the air flow path can be increased, and there is an effect that air is taken in more efficiently.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view schematically showing a fuel cell single-layer cell 10 (hereinafter referred to as a fuel cell 10) in an embodiment of the present invention.

  A schematic configuration of the fuel cell 10 will be described with reference to FIG. The fuel cell 10 is provided with a pair of plates 11 and 12 including a fuel electrode layer side plate 11 and an oxidant electrode layer side plate 12, and an insulating material 19. As described with reference to FIG. 2, a membrane electrode assembly 13 (hereinafter referred to as MEA 13) is interposed between the pair of plates 11 and 12. An insulating material 19 is provided so as to surround the end of the MEA 13.

  As shown in FIG. 1, bolt insertion holes 20 are provided at the edges of the rectangular plates 11 and 12 in plan view. Then, when the tightening bolt inserted into the bolt insertion hole 20 is screwed into the nut, the pair of plates 11 and 12 are clamped, and the MEA 13 interposed between the plates 11 and 12 is in the thickness direction. Pressed. Thereby, contact resistance can be reduced.

  The direction in which the pair of plates 11 and 12 face each other is hereinafter referred to as the up-and-down direction of the fuel cell 10, and the longitudinal direction of the pair of plates 12 in plan view is hereinafter referred to as the longitudinal direction of the fuel cell 10 and A direction perpendicular to the longitudinal direction of the plate 12 in plan view is hereinafter referred to as a lateral direction of the fuel cell 10. The fuel cell 10 is used with the outer surface of the oxidant electrode layer side plate 12 facing upward.

  As shown in FIG. 1, the upper surface 12a of the oxidant electrode layer side plate 12 is provided with openings 31a at the upper end of the air flow path 31 aligned at a predetermined pitch in the vertical and horizontal directions. On the other hand, the opening 32a of the air introduction path 32 is provided in the end surface 12c of the oxidant electrode layer side plate 12. The fuel cell 10 is configured to take in sufficient air into the interior and obtain a high output density by utilizing the chimney effect generated in the air flow path 31 provided in the oxidant electrode layer side plate 12. .

  With reference to FIG. 2A and FIG. 2B, the air flow path 31 and the air introduction path 32 provided in the oxidant electrode layer electrode side plate 12 will be described. FIG. 2A is a plan view and a cross-sectional view schematically showing an enlarged part of the fuel cell 10 described with reference to FIG.

  As shown in FIG. 2A, the fuel electrode layer side plate 11 is configured by laminating a plurality of plate-like members. Although the fuel electrode layer side plate 11 is formed with a fuel flow path for supplying fuel gas to the MEA 13, illustration and description thereof are omitted. As the fuel gas, hydrogen or a gas containing hydrogen is used. On the other hand, as the oxidant gas, air is supplied through the air flow path 31 as described above. Fuel gas and air are referred to as reaction gases.

  The oxidant electrode layer side plate 12 is provided with a large number of air flow paths 31 and air introduction paths 32. The air flow path 31 is a hole communicating from the upper surface 12a to the lower surface 12b of the oxidant electrode layer side plate 12 in a direction substantially perpendicular to the surface of the oxidant electrode layer 16 (see FIG. 3). They are arranged in the horizontal direction with a predetermined pitch. On the other hand, the air introduction path 32 has an opening 32 a opened to the outside, and communicates with the air flow path 31.

  With reference to FIG.2 (b), the flow of the air by a chimney effect is demonstrated. FIG. 2B is a cross-sectional view schematically showing the air flow path 31 and the air introduction path 32. As shown in FIG. 2B, when heat is generated by the power generation in the MEA 13, the air warmed by the heat rises in the air flow path 31 and is discharged from the upper end opening 31a opened to the outside. Therefore, a negative pressure is generated in the air flow path 31. Therefore, a large amount of air is taken into the air flow path 31 through the air introduction path 32 communicating with the air flow path 31. Therefore, according to the fuel cell 10, a high load output is possible and a high output density is obtained.

  With reference to FIG. 2A again, more detailed configurations of the air flow path 31 and the air introduction path 32 will be described. As shown in FIG. 2A, the oxidant electrode layer side plate 12 includes a current collecting plate 121 that contacts the oxidant electrode layer 16 (see FIG. 3) of the MEA 13 and an insulating plate that contacts the current collecting plate 121. 122 and an end plate 123 that contacts the insulating plate 122 are laminated in the thickness direction. The surface of the current collector plate 121 that contacts the MEA 13 constitutes the lower surface 12 b of the oxidant electrode layer side plate 12.

  Further, as described above, since the oxidant electrode layer plate 12 is fastened to the fuel electrode layer side plate 11, the end plate 123 is made of, for example, duralumin and has sufficient strength to give strength. It has a thickness. The outer surface of the oxidant electrode layer plate 12 (that is, the surface opposite to the surface in contact with the insulating plate 122) constitutes the upper surface 12a of the oxidant electrode layer side plate 12. The oxidant electrode layer side plate 12 may be laminated with other members of the current collecting plate 121, the insulating plate 122, and the end plate 123.

  Here, as shown in FIG. 2A, the air introduction path 32 is provided at the height of the current collecting plate 121 and the insulating plate 122 so as to cross or longitudinally cross these. For this reason, as shown in FIG. 2B, the air introduction path 32 communicates with the air flow path 31 in the vicinity of the oxidant electrode layer 16 (see FIG. 3) of the MEA 13, and the oxidant electrode layer 16 of the MEA 13. Air is efficiently supplied to (see FIG. 3).

  The air introduction path 32 communicates in a straight line from the opening 32 a of the end face 12 c of the oxidant electrode layer side plate 12 to the air flow path 31 in a direction perpendicular to the thickness direction of the oxidant electrode layer side plate 12. Therefore, pressure loss can be reduced and more air can be taken into the air flow path.

  The opening 32a of the air introduction path 32 is provided on the end face 12c (see FIG. 1) of the oxidant electrode layer plate 12. In this way, the distance between the air introduction passage opening 32a and the air flow passage opening 31a can be increased, and a higher effect can be obtained.

  Here, the air introduction path 32 is disposed so as to communicate from one end face 12 c facing the longitudinal direction of the oxidant electrode layer side plate 12 to the other end face 12 c, and the oxidant electrode layer side plate 12. It arrange | positions so that it may connect from a pair of end surface 12c opposed to a horizontal direction to the other end surface 12c. That is, the air introduction path 32 is provided in a lattice shape in the plan view of the oxidant electrode layer side plate 12. The air flow path 31 and the air introduction path 32 communicate with each other at the intersection of the two air introduction paths 32. In this way, at least two air introduction paths 32 are communicated with one air flow path 31, and a large amount of air is efficiently taken into the air flow path 31.

The air flow path 31 and the air introduction path 32, the diameter of the opening 31a of the air passage 31 (hereinafter, referred to as opening diameter _{D 31)} is the diameter of the opening 32a of the air introduction passage 32 (hereinafter, the aperture diameter _{D 32} It is comprised so that it may become larger than this. Therefore, the air heated in the vicinity of the oxidant electrode layer side plate 12 is efficiently exhausted from the opening 31 a of the air flow path 31, and a large amount of air can be taken into the air flow path 31. Here, the opening diameter D ₃₁ of the air passage 31 and configured to be at least twice the aperture diameter D ₃₂ of the air introduction path 32, it is possible to obtain a more remarkable effect.

The length of the air flow path 31 in the direction perpendicular to the surface of the oxidant electrode layer 16 (hereinafter referred to as the piping length L _{31 of} the air flow path 31) is the opening diameter D ₃₁ of the air flow path ₃₁ . It is comprised so that it may become 2 times or more. The chimney effect is more effective as the pipe length of the chimney portion (corresponding to the air flow path 31) for exhausting air is longer. Therefore, by configuring in this way, the effect of taking air into the air flow path 31 is obtained. Can be increased.

Further, the air introduction path 32 has a distance from the opening 32 a to the air flow path 31 (hereinafter referred to as a pipe length L ₃₂ of the air introduction path 32) smaller than the pipe length L ₃₁ of the air flow path 31. It is configured as follows. Therefore, the pressure loss of suction is reduced, and air is taken into the air flow path 31 efficiently.

  The air flow path 31 and the air introduction path 32 are configured in a cylindrical shape. Therefore, pressure loss is further reduced and air is taken in efficiently.

As described above, in order to reduce the contact resistance, the pair of plates 11 and 12 are connected to each other so that the MEA 13 is pressed in the thickness direction. Therefore, the thickness of the pair of plates 11 and 12 is increased in order to obtain strength. When the air flow path 31 is provided so as to penetrate the oxidant electrode layer side plate 12 in the thickness direction, the pipe length L ₃₁ of the air flow path 31 becomes large, so that the chimney effect is further increased, Air can be taken into the air flow path.

  FIG. 3 is a cross-sectional view schematically showing the main part of the MEA 13. As shown in FIG. 3, the MEA 13 is configured by laminating a polymer electrolyte membrane 17 in a state of being interposed between an oxidant electrode layer 16 and a fuel electrode layer 18.

  As shown in FIG. 3, the MEA 13 includes a polymer electrolyte membrane 17, an oxidant electrode layer 16 that contacts one surface of the polymer electrolyte membrane 17, and a fuel that contacts the other surface of the polymer electrolyte membrane 17. An electrode layer 18 is provided.

  The polymer electrolyte membrane 17 is made of Nafion (registered trademark). The polymer electrolyte membrane is a substance excellent in corrosion resistance, heat resistance and durability, and has a function of separating the fuel and the oxidant, and the hydrogen ion generated in the fuel electrode layer is converted into the oxidant electrode. A membrane having the function of transporting to the layer is used. For example, a perfluorosulfonic acid ion exchange membrane, a hydrocarbon solid electrolyte membrane, or the like is used.

  The oxidant electrode layer 16 includes a reaction layer 161 and a diffusion layer 162, and the fuel electrode layer 18 includes a reaction layer 181 and a diffusion layer 182. The reaction layers 161 and 181 are layers containing a substance having catalytic activity, and the diffusion layers 162 and 182 are layers that promote the diffusion of the reaction gas, but the oxidant electrode layer 16 and the fuel electrode layer 18 A layer other than the reaction layer and the diffusion layer may be further added.

  The diffusion layer 162 of the oxidant electrode layer 16 is a porous first layer containing a carbon powder and a water repellent resin on both sides of a diffusion layer base material 162a made of carbon woven fabric or carbon paper capable of gas diffusion. A first microporous layer 162b and a second microporous layer 162c are formed. Further, a reaction layer 161 containing carbon carrying a platinum catalyst and a Nafion ionomer is formed on the first microporous layer 162b side.

  Similarly, the diffusion layer 182 of the fuel electrode layer 18 has a porous structure containing carbon powder and a water-repellent resin on both sides of a diffusion layer base material 182a made of carbon woven fabric, carbon paper or the like capable of gas diffusion. A first microporous layer 182b and a second microporous layer 182c are formed. Further, a reaction layer 181 containing carbon carrying a platinum catalyst and a Nafion ionomer is formed on the first microporous layer 182b side.

  As the diffusion layer base materials 162a and 182a, for example, carbon cloth, carbon paper, a nonwoven fabric made of carbon fiber, or the like can be used. The first microporous layers 162b and 182b and the second microporous layers 162c and 182c can be a mixture of water-repellent resin powder and carbon powder. Specific examples of the water-repellent resin powder include fluorocarbon polymers (for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA)). ), Polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), ethylene / tetrafluoroethylene copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), etc. ). Examples of the carbon powder include carbon black, graphite powder, carbon nanofiber, furnace black, and acetylene black.

  In the fuel cell 10 configured as described above, the diffusion layer 162 of the oxidant electrode layer 16 is exposed to air by the air flow path 31 provided in the oxidant electrode layer side plate 12, but is generated in the reaction layer 161. The absorbed water is sucked into the diffusion layer 162 and held in the diffusion layer 162. For this reason, water is held in the diffusion layer 162, and the amount that is evaporated away into the air is reduced. Therefore, drying of the polymer electrolyte membrane 17 and the oxidant electrode layer 16 and an accompanying increase in internal resistance can be suppressed without relying on external humidification. As a result, the power density can be improved even in a fuel cell that does not include an auxiliary device for supplying air.

  In particular, since the first microporous layer 162b having a pore size much smaller than that of the diffusion layer substrate 162a is provided on the reaction layer 161 side of the diffusion layer substrate 162a on the oxidant electrode layer 16 side, It is easy to permeate and liquid water is difficult to permeate. Therefore, excess water that hinders the diffusion of the oxidizing gas can be discharged to the diffusion layer base material 162a, and the MEA 13 can be prevented from drying.

  Further, since the second microporous layer 162c also has a pore size much smaller than that of the diffusion layer base material 162a, the liquid does not substantially pass through the gas, and the water in the diffusion layer base material 162a is in a state of water vapor. It can only move to the air channel 31 side (see FIG. 1). For this reason, the water produced | generated by the reaction layer can be sucked out and hold | maintained to the diffusion layer base material 162a, and when the reaction layer 161 dries, the water currently hold | maintained can be supplied. For this reason, drying of MEA13 can be prevented highly.

  Further, the first microporous layer 182b and the second microporous layer 182c similar to the oxidant electrode layer 16 are also formed on the fuel electrode layer 18 side. For this reason, not only the oxidant electrode layer 16 side but also the amount of water back-diffused from the oxidant electrode layer 16 to the fuel electrode layer 18 is evaporated and carried away into the fuel gas, and the MEA 13 is further dried. Can be prevented.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.

  For example, the present invention can be applied to a polymer electrolyte fuel cell (PEFC) that supplies fuel gas, and can also be applied to a direct methanol fuel cell (DMFC) that directly generates power from methanol.

Further, for example, in the above-described embodiment, an example of the size relationship between the opening diameter D ₃₁ of the air flow path 31, the pipe length L ₃₁ , the opening diameter D ₃₂ of the air introduction path 32, and the pipe length L ₃₂ has been described. Is not limited to this example, and specific values for the air flow path 31 and the air introduction path 32 can be appropriately designed according to the operating conditions of the fuel cell. The operating conditions referred to here are, for example, conditions relating to the amount of air necessary for the fuel cell 10 and the amount of heat generated by the fuel cell 10. If operation at a high current density is assumed, the required air volume becomes large. Therefore, in such a case, increasing the thickness of the end plate 123 by a pipe length L ₃₁ of the air passage 31 to the large, to be able to incorporate a larger amount of air, changing the design good.

  Moreover, although the shape in planar view of a pair of plates 11 and 12 demonstrated as what was a rectangle in the said embodiment, another shape may be sufficient.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited based on these Examples.
Example 1
A fine powder of polytetrafluoroethylene is mixed with the carbon black powder (primary particle diameter 16 nm) so as to be 35 parts by weight, and then a plain weave carbon cloth is prepared. It was sandwiched and integrated by thermocompression bonding at 345 ° C.

Next, 2 g to 200 g of Nafion (registered trademark) solution (5 wt% water / isopropanol solution) is added to 1 g of commercially available platinum-supporting carbon (platinum content 60 wt%), and stirred with a hybrid mixer to obtain a catalyst paste. The surface of the film integrated by the method was printed so that the amount of Pt supported was 0.01 to ² mg / cm ² and dried to obtain a diffusion layer with a reaction layer.

  Instead of printing on the diffusion layer to form the reaction layer, the catalyst paste is printed on a polytetrafluoroethylene sheet, dried and then peeled to produce a self-supporting reaction layer film. May be thermocompression-bonded with the diffusion layer to form a diffusion layer with a reaction layer.

  The diffusion layer with a reaction layer produced as described above is prepared as an oxidant electrode layer 16 and a fuel electrode layer 18, and sandwiched between reaction layers from both sides of a polymer electrolyte membrane made of Nafion (registered trademark), and hot-pressed. Crimped. Furthermore, using this as MEA13, the fuel electrode layer side plate 11 and the oxidant electrode layer side plate 12 were provided on the outer side, and the fuel cell 10 of Example 1 was produced.

The oxidant electrode layer side plate 12 is provided with an air flow path 31 and an air introduction path 32.
(Comparative example)
In the comparative example, as the oxidant electrode layer side plate, a fuel cell was configured using a plate provided with the air flow path 31 but not provided with the air introduction path 32. Others are the same as the fuel cell 10 of Example 1, and description is abbreviate | omitted.
<Evaluation>
A hydrogen gas supply device was connected to the fuel gas passages of Example 1 and the comparative example manufactured in this way, and dried hydrogen gas was introduced from the hydrogen gas supply device, and the cell voltage was measured. As described above, air was supplied to the oxidizer electrode layer by natural diffusion or natural convection without using an auxiliary machine such as a pump or blower.

  FIG. 4 is a graph showing the relationship between the energization current and the cell voltage of the fuel cells of Example 1 and Comparative Example. In FIG. 4, the horizontal axis indicates the energization current of the fuel cell, and the vertical axis indicates the measured cell voltage. As shown in FIG. 4, the voltage drop in Example 1 is small even at a high current, whereas the voltage in the comparative example is greatly reduced on the high current side as compared with Example 1. This is because, in Comparative Example 1, air supply shortage occurs on the high current side, and as a result, the voltage is greatly reduced, whereas in Example 1, the supply of air is promoted by the chimney effect. This is because the voltage drop due to the shortage hardly occurs. From the above results, it was found that in the fuel cell of Example 1, sufficient air was taken into the air flow path using the chimney effect, and a high output density was obtained.

1 is a perspective view schematically showing a fuel cell in an embodiment of the present invention. (A) is a plan view and a cross-sectional view schematically showing an enlarged part of the fuel cell, and (b) is a cross-sectional view schematically showing an air flow path and an air introduction path. It is sectional drawing which shows the principal part of MEA typically. It is a graph which shows the experimental result which measured the cell voltage when the electricity supply current was changed in the fuel cell of Example 1 and a comparative example. (A) is a figure which shows the conventional passive type fuel cell, (b) is a figure which shows typically the structure of the air supply part of the passive type fuel cell shown to (a).

Explanation of symbols

10 Fuel Cell 12 Oxidant Electrode Layer Side Plate 12c End Face 13 MEA
16 Oxidant Electrode Layer 17 Solid Polymer Electrolyte Membrane 18 Fuel Electrode Layer 31 Air Channel 31a Upper Opening 32 Air Introducing Channel 32a Opening D ₃₁ Air Channel Upper End Diameter L ₃₁ Distance from Lower End to Upper End of Air Channel D ₃₂ Opening diameter of air introduction path L ₃₂ Distance from opening to air flow path

Claims (6)

In a fuel cell having a membrane electrode assembly in which both sides of a solid polymer electrolyte are sandwiched between a fuel electrode layer composed of a reaction layer and a diffusion layer and an oxidant electrode layer,
A fuel electrode layer side plate disposed on both sides of the membrane electrode assembly, in which a fuel flow path is formed; and an oxidant electrode layer side plate in which an air flow path is formed;
The air flow path is formed through the plate substantially perpendicular to the surface of the oxidant electrode layer,
The oxidant electrode layer side plate is formed with an air introduction path in which one opening is opened to the outside and the other opening communicates with the oxidant electrode layer in the air flow path. Fuel cell.   The fuel cell according to claim 1, wherein an opening diameter of the air flow path is configured to be larger than an opening diameter of the air introduction path.   The air flow path is configured such that a distance in a direction substantially perpendicular to the surface of the oxidant electrode layer is at least twice the opening diameter of the air flow path. 3. The fuel cell according to 1 or 2.   The air introduction path is configured such that the distance from the opening opened to the outside to the air flow path is smaller than the distance of the air flow path in a direction substantially perpendicular to the surface of the oxidant electrode layer. The fuel cell according to any one of claims 1 to 3, wherein the fuel cell is formed.   The fuel cell according to claim 1, wherein the air flow path and the air introduction path are configured in a cylindrical shape.   6. The fuel cell according to claim 1, wherein the opening of the air introduction path is provided on an end surface of the oxidant electrode layer side plate.

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