JP2004185904A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell effectively restricted in generation of the heat and effectively restricted in lowering of an output during the use. <P>SOLUTION: This fuel cell has the stack structure formed by laminating unit cells respectively provided with an electrolyte film 30, a fuel electrode 31 arranged on one side of the electrolyte film 30 and an air electrode 32 arranged on the other side of the electrolyte film 30. Thickness of a gas diffusion layer of the air electrode 32 is formed thinner than the thickness of a gas diffusion layer of the fuel electrode 31. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell having a stack structure.
[0002]
[Prior art]
2. Description of the Related Art In recent years, fuel cells have attracted attention as a power source that has high energy conversion efficiency and does not generate harmful substances due to power generation reactions. As one of such fuel cells, a polymer electrolyte fuel cell that operates at a low temperature of 100 ° C. or less is known.
[0003]
FIG. 7 is an explanatory diagram for explaining the principle of a conventional general polymer electrolyte fuel cell.
[0004]
As shown in FIG. 7, the polymer electrolyte fuel cell has a basic structure in which a solid polymer membrane, which is an electrolyte membrane, is disposed between a fuel electrode and an air electrode. Is a device that generates electricity by the following electrochemical reaction.
[0005]
Fuel _{^{electrode: H 2 → 2H + + 2e}} - (1)
Air electrode: 1 / 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (2)
The fuel electrode and the air electrode have a structure in which a catalyst layer and a gas diffusion layer are stacked. The catalyst layers of the respective electrodes are opposed to each other with the solid polymer film interposed therebetween, and constitute a fuel cell. The catalyst layer is a layer formed by binding carbon particles carrying a catalyst with an ion exchange resin. The gas diffusion layer serves as a passage for oxygen and hydrogen. The power generation reaction proceeds at a so-called three-phase interface between the catalyst, the ion exchange resin, and hydrogen in the catalyst layer.
[0006]
At the fuel electrode, hydrogen contained in the supplied fuel is decomposed into hydrogen ions and electrons as shown in the above formula (1). Among them, hydrogen ions move inside the solid polymer electrolyte membrane toward the oxygen electrode, and electrons move to the oxidant electrode (air electrode) through an external circuit. On the other hand, in the oxidant electrode, oxygen contained in the oxidant (air) supplied to the oxygen electrode (air electrode) reacts with the hydrogen ions and electrons moved from the fuel electrode, and is expressed by the above equation (2). Water is produced. As described above, in the external circuit, the electrons move from the fuel electrode toward the air electrode, so that electric power is extracted.
[0007]
FIG. 8 is a diagram showing a structure of a unit cell constituting a stack structure fuel cell. This unit cell has a structure in which a fuel electrode catalyst layer and a gas diffusion layer are arranged on one surface of a solid polymer film, and an air electrode catalyst layer and a gas diffusion layer are arranged on the other surface. This structure is called (MEA / Membrane Electrode Assembly). The MEA, a fuel electrode separator including a flow path of fuel gas as a reaction gas, and an air electrode separator including a flow path of air are stacked to form a unit cell. A water separator (cooling plate) is provided between the unit cells.
[0008]
FIG. 9 is a sectional view showing a cell stack configuration. As shown in FIG. 9, the cell stack forming the battery main body is formed by stacking a plurality of basic cells as shown in FIG. 8 (however, the cell shown in FIG. 9 is replaced by the cell shown in FIG. 8). Is not exactly the same configuration). Metal current collectors are arranged at both ends of the cell stack, and these are used as external current extraction terminals.
[0009]
In such a cell stack, suppressing heat generation in the cell is an important technical problem. At the air electrode, an exothermic reaction for purifying water proceeds. Due to this heat generation, the water in the cell evaporates, and the water evaporated by the gas of the air electrode or the fuel electrode is discharged to the outside. When the water content in the cell tends to be insufficient, the hydrogen ion conductivity decreases, and the output of the battery decreases. Therefore, there is a need for a technique for effectively suppressing the heat generation of the cell.
[0010]
Patent Literature 1 describes an example of a technique for suppressing heat generation due to such a battery reaction. The fuel cell described in this document has a fuel cell stack body in which unit cells and fuel cell separators are alternately stacked, and supplies cooling water along the stacking direction of the unit cells and the fuel cell separator. A cooling water manifold for passage is provided.
[0011]
[Patent Document 1]
JP 2001-6714 A
[Problems to be solved by the invention]
However, it is difficult to always obtain sufficient cooling efficiency with the conventional technology as described in Patent Document 1. In particular, drying of moisture due to heat generation becomes remarkable on the air electrode side where the amount of exothermic reaction is large.
[0013]
Further, in the conventional fuel cell, management of operating conditions of the fuel cell becomes complicated, and particularly, moisture management becomes difficult. For this reason, stabilizing the battery output has not been easy. Further, in the above-mentioned conventional fuel cell, the amount of heat generated by the entire fuel cell increases, so that in order to obtain a sufficient cooling capacity, the mechanism required for that becomes complicated and large-scale, and it is difficult to reduce the size of the device. Become.
[0014]
The present invention has been made in view of the above-described conventional problems, and has as its object to provide a fuel cell in which heat generation of the fuel cell is effectively suppressed, and a decrease in output during use is effectively suppressed. .
[0015]
[Means for Solving the Problems]
The fuel cell according to the present invention has a fuel electrode on one surface of a solid electrolyte membrane, a plurality of unit cells having an air electrode disposed on the other surface, a plurality of unit cells are stacked, and the air electrode of one unit cell and the other adjacent cells are stacked. A fuel cell having a stack structure in which a cooling channel is arranged between a fuel electrode of a unit cell,
Of the air electrode of the one unit cell and the fuel electrode of the other unit cell, the heat removal capacity of the cooling flow path for one of the electrodes is smaller than the heat removal capacity of the cooling flow path for the other electrode. It is characterized in that it is configured to be large.
[0016]
According to the present invention, it is configured that one electrode adjacent to the cooling channel is cooled more preferentially than the other electrode. Generally, each electrode of a fuel cell generates more heat on one side than on the other. When hydrogen is used as the fuel, the heat generated at the air electrode increases. When a liquid fuel such as methanol is used, the heat generated at the fuel electrode increases. The present invention distributes a large amount of the cooling effect to such an electrode generating more heat. As a result, it is possible to effectively suppress the temperature rise on the electrode side where the amount of heat generated by combustion is large. As a result, when the battery is used, it is possible to effectively prevent the battery output from decreasing with time.
[0017]
In the fuel cell according to the aspect of the invention, the one electrode may be configured to have higher thermal conductivity than the other electrode. By doing so, the temperature rise on the air electrode side can be suppressed more effectively.
For example, the thickness of the one electrode may be smaller than the thickness of the other electrode. If the materials forming the electrodes are substantially the same, the thermal conductivity can be improved by reducing the thickness.
Further, the one electrode may be provided with a gas diffusion layer containing a good heat conductive filler. The electrode usually has a configuration including a gas diffusion layer and a catalyst layer, and the thermal conductivity can be improved by introducing a good thermal conductive filler into the gas diffusion layer.
[0018]
Further, in the fuel cell of the present invention, the distance between the one electrode and the cooling channel may be shorter than the distance between the other electrode and the cooling channel. By doing so, the temperature rise on the air electrode side can be suppressed more effectively. The term “distance” as used herein refers to the distance between the diffusion layer and the cooling channel when each electrode is formed by laminating a catalyst layer and a diffusion layer in this order from the solid electrolyte membrane side. Paying attention to the distance from the cooling channel, the distance between the catalyst layer of the one electrode and the cooling channel is shorter than the distance between the catalyst layer of the other electrode and the cooling channel. With this configuration, the cooling effect intended by the present invention can be obtained more reliably.
[0019]
Further, in the present invention, a cooling plate including the cooling flow path is disposed between the one unit cell and the other unit cell, and the cooling plate is disposed adjacent to the one electrode and has a flow of air. A first plate having a flow path and a flow groove for cooling water, and a second plate having a flow path for fuel gas and a flow path for cooling water adjacent to the other electrode, the flow path comprising: It has a structure in which the surfaces provided with the grooves are stacked in contact with each other, and the cooling channels can be configured such that the channel grooves of the respective plates are integrated. When this configuration is adopted, the flow channel through which the cooling water flows and the flow channel through which the fuel gas and the air pass are formed in one plate, so that the cooling effect by the cooling flow channel becomes more remarkable. Therefore, when the battery is used, it is possible to more effectively suppress the battery output from decreasing over time.
In the present invention, the one electrode may be an air electrode, and the other electrode may be a fuel electrode. When the fuel is hydrogen, the heat generation on the air electrode side is larger than the heat generation on the fuel electrode side, so this configuration is effective.
In the present invention, the one electrode may be a fuel electrode, and the other electrode may be an air electrode. When the fuel is a liquid fuel such as methanol or the like, the heat generation on the fuel electrode side is larger than the heat generation on the air electrode side, so this configuration is effective.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention improves the cooling efficiency of an air electrode that generates a large amount of heat, among the constituent members of a unit cell. The following are exemplified as specific means.
[0021]
(I) The thermal conductivity of the air electrode side, especially the gas diffusion layer, is made higher than the thermal conductivity of the fuel electrode side, especially the gas diffusion layer. Further, as a means for realizing this, the thickness of the gas diffusion layer of the air electrode is made smaller than the thickness of the gas diffusion layer of the fuel electrode, or the fuel electrode catalyst layer and its Add more thermally conductive material than the gas diffusion layer or reduce porosity.
[0022]
(Ii) By making the physical distance between the air electrode and the cooling water shorter than the physical distance between the fuel electrode and the cooling water, the cooling effect of the cooling water at the air electrode by the cooling water at the fuel electrode is reduced. Increase than the cooling effect.
[0023]
(Iii) The contact area between the cooling water on the air electrode side and the cooling plate is made larger than the contact area between the cooling water on the fuel electrode side and the cooling plate.
[0024]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0025]
[First Embodiment]
In the present embodiment, by forming the air electrode of each unit cell constituting the stack thinner than the fuel electrode, the heat conductivity of the air electrode is made higher than that of the fuel electrode, and the cooling efficiency of the air electrode is increased. I have.
[0026]
FIG. 1 is a configuration diagram illustrating a unit cell of the fuel cell according to the first embodiment.
[0027]
In FIG. 1, a unit cell of the fuel cell according to the present embodiment includes an electrolyte membrane 10 formed of a solid polymer, a fuel electrode 11 disposed on one side of the electrolyte membrane 10, and the other side of the electrolyte membrane 10. And the air electrode 12 arranged at the center.
[0028]
It is assumed that the thickness of the gas diffusion layer of the cathode 12 is smaller than the thickness of the gas diffusion layer of the anode 11. The thickness reduction rate can be configured to be at least 20% or more.
[0029]
The electrolyte membrane 10 can be formed using an ion exchange resin.
[0030]
Hereinafter, functions related to the cooling effect around the unit cell of the fuel cell according to the present embodiment will be described.
[0031]
Since the thickness of the gas diffusion layer of the air electrode 12 is formed to be smaller than the thickness of the gas diffusion layer of the fuel electrode 11, the thermal conductivity of the gas diffusion layer on the air electrode 12 side is Is higher than the thermal conductivity of the gas diffusion layer (in this case, the thermal conduction speed is increased). For this reason, the cooling effect from the cooling water increases on the side of the air electrode 12, and the temperature rise on the side of the air electrode 12 that generates a large amount of heat can be suppressed.
[0032]
FIG. 2 schematically shows a cross-sectional structure of a fuel cell using the unit cells according to the first embodiment.
[0033]
The fuel cell shown in FIG. 2 includes a flat unit cell 150, and separators 134 and 136 are provided on both sides of the unit cell 150. Although only one unit cell 150 is shown in this example, a fuel cell may be formed by stacking a plurality of unit cells 150 via the separator 134 or the separator 136 (see FIG. 4 described later).
[0034]
The unit cell 150 has the electrolyte membrane 10 made of a solid polymer, the fuel electrode 11, and the air electrode 12 (see FIG. 1).
[0035]
In FIG. 2, for the sake of easy understanding, the fuel electrode 11 and the air electrode 12 are drawn so that no difference in thickness is seen. However, in the case of the present embodiment, actually, as shown in FIG. The thickness of the air electrode 12 is smaller than that of the fuel electrode 11.
[0036]
The fuel electrode 11 has a stacked catalyst layer 130 and a gas diffusion layer 132, and the air electrode 12 also has a stacked catalyst layer 126 and a gas diffusion layer 128. The catalyst layer 130 of the fuel electrode 11 and the catalyst layer 126 of the air electrode 12 are provided to face each other with the electrolyte membrane 10 made of a solid polymer interposed therebetween.
[0037]
A gas channel 140 is provided in the separator 136 provided on the fuel electrode 11 side, and fuel gas is supplied to the unit cells 150 through the gas channel 140. Similarly, a gas passage 138 is also provided in the separator 134 provided on the air electrode 12 side, and oxygen is supplied to the unit cell 150 through the gas passage 138. More specifically, during operation of the fuel cell, a reforming gas, for example, hydrogen gas is supplied from the gas flow channel 140 to the fuel electrode 11, and an oxidizing gas, for example, air is supplied from the gas flow channel 138 to the air electrode 12. Is done. Thereby, a power generation reaction occurs in the unit cell 150.
[0038]
When hydrogen gas is supplied to the catalyst layer 130 through the gas diffusion layer 132, hydrogen in the gas becomes protons, and the protons move to the air electrode 12 side in the electrolyte membrane 10 made of a solid polymer. At this time, the electrons emitted from the fuel electrode 11 move to an external circuit and flow into the air electrode 12 via the external circuit. On the other hand, when air is supplied to the catalyst layer 126 via the gas diffusion layer 128, oxygen ions combine with protons to form water. As a result, in the external circuit, electrons flow from the fuel electrode 11 to the air electrode 12, and power can be taken out.
[0039]
The electrolyte membrane 10 made of a solid polymer exhibits good ion conductivity in a wet state, and functions as an ion exchange membrane for transferring protons between the fuel electrode 11 and the air electrode 12. The electrolyte membrane 10 can be formed of a solid polymer material such as a fluorine-containing polymer, for example, a sulfonic acid type perfluorocarbon polymer, a polysulfone resin, a perfluorocarbon polymer having a phosphonic acid group or a carboxylic acid group. Combination or the like can be used. Examples of the sulfonic acid-type perfluorocarbon polymer include Nafion (registered trademark) 112 and the like.
[0040]
The gas diffusion layer 132 in the fuel electrode 11 and the gas diffusion layer 128 in the air electrode 12 have a function of supplying the supplied hydrogen gas or air to the catalyst layers 130 and 126. It also has a function of transferring electric charges generated by the power generation reaction to an external circuit and a function of discharging water, unreacted gas, and the like to the outside. The gas diffusion layer 132 and the gas diffusion layer 128 are preferably made of a porous body having electron conductivity, and can be made of, for example, carbon paper or carbon cloth.
[0041]
The catalyst layer 130 in the fuel electrode 11 and the catalyst layer 126 in the air electrode 12 are porous membranes, and are preferably composed of ion exchange resin particles and carbon particles carrying a catalyst. The ion exchange resin particles have a function of electrically connecting the carbon particles supporting the catalyst and the electrolyte membrane 10 made of a solid polymer. The fuel electrode 11 is required to have proton permeability, and the air electrode 12 is required to have oxygen permeability. The ion exchange resin particles may be formed from the same polymer material as the electrolyte membrane 10. Examples of the catalyst include platinum, ruthenium, rhodium and alloys thereof. Examples of the carbon particles that support the catalyst include acetylene black, Ketjen black, and carbon nanotubes. The catalyst layer 126 in the air electrode 12 may optionally contain an additive for improving thermal conductivity.
[0042]
Hereinafter, an example of a method for manufacturing the unit cell 150 will be described. First, in order to produce the fuel electrode 11 and the air electrode 12, a catalyst such as platinum is supported on carbon particles using, for example, an impregnation method. Next, the catalyst-carried ink is generated by dispersing the carbon particles carrying the catalyst and the ion-exchange resin particles in a solvent. This catalyst ink is applied to, for example, carbon paper to be a gas diffusion layer, heated and dried to produce the fuel electrode 11 and the air electrode 12. As an application method, for example, a technique of brush application or spray application may be used.
[0043]
Subsequently, the electrolyte membrane 10 made of a solid polymer is sandwiched between the catalyst layer 130 of the fuel electrode 11 and the catalyst layer 126 of the air electrode 12, and joined by hot pressing. Thus, a unit cell 150 is manufactured. When the ion exchange resin particles in the electrolyte membrane 10 made of a solid polymer and the catalyst layers 130 and 126 are made of a polymer material having a softening point or a glass transition, hot pressing is performed at a temperature exceeding the softening temperature or the glass transition temperature. Is preferably performed.
[0044]
FIG. 3 schematically shows a detailed cross-sectional structure of the unit cell according to the first embodiment.
[0045]
FIG. 4 schematically illustrates a configuration of a stack structure of the fuel cell according to the first embodiment.
[0046]
The unit cell shown in FIG. 1 corresponds to the unit cell 15 in FIG. 4, and includes an electrolyte membrane 10 formed of a solid polymer and a catalyst layer of a fuel electrode 11 disposed on one side of the electrolyte membrane 10. And the diffusion layer 16, and the catalyst layer and the diffusion layer 16 of the air electrode 12 arranged on the other side of the electrolyte membrane 10. A plate having an air flow path 18 is disposed on the air electrode side of the unit cell 15, and a plate having a fuel flow path 17 is disposed on the fuel electrode side. A plate provided with a circulating water channel 151 is provided so as to be in contact with the plate.
[0047]
According to this embodiment, the thickness of the gas diffusion layer of the air electrode 12 is formed to be smaller than the thickness of the gas diffusion layer of the fuel electrode 11, so that the heat conductivity of the gas diffusion layer on the air electrode 12 side is reduced. It can be higher than the thermal conductivity of the gas diffusion layer on the pole 11 side. For this reason, the cooling effect of the cooling water such as the cooling water increases on the air electrode 12 side, and the temperature rise on the air electrode 12 side, which generates a large amount of heat as compared with the fuel electrode 11 side, can be more effectively suppressed. . As a result, when the battery is used, it is possible to effectively prevent the battery output from decreasing with time.
[0048]
In the present embodiment, the thickness of the gas diffusion layer of the air electrode 12 is made smaller than the thickness of the fuel electrode 11 as a means for increasing the thermal conductivity on the air electrode 12 side. By changing the shape, size, and material of the electrodes, it is possible to suppress the temperature rise of the electrode that generates a large amount of heat.
Further, the gas diffusion layer of the air electrode 12 may contain a good heat conductive filler such as carbon. By doing so, the air electrode can be cooled more efficiently.
[0049]
[Second embodiment]
FIG. 5 schematically shows a configuration of the fuel cell according to the second embodiment.
[0050]
In the figure, the fuel cell according to the present embodiment includes a plurality of unit cells, a fuel passage 23, an air passage 24, a circulating water passage 25, a gasket 26, an anode cooling plate 27, And a plate 28.
[0051]
The unit cell includes an electrolyte membrane 20 formed of a solid polymer, a fuel electrode 21 disposed on one side of the electrolyte membrane 20, and an air electrode 22 disposed on the other side of the electrolyte membrane 20. .
[0052]
The fuel passage 23 is formed in an anode cooling plate 27 in which the anode 21 is stored. The air passage 24 is formed in an air electrode cooling plate 28 in which the air electrode 22 is stored. When the physical distance between the circulating water flow path 25 and the fuel electrode 21 is a, and the physical distance between the circulating water flow path 25 and the air electrode 22 is b, The arrangement satisfies the condition of a> b. In the present embodiment, the fuel electrode 21 and the air electrode 22 each have a configuration in which a catalyst layer and a diffusion layer are stacked in this order from the solid electrolyte membrane side, and the circulating water flow path 25 and the fuel electrode 21 When the physical distance between the catalyst layer and the circulating water channel 25 and the air electrode 22 catalyst layer is B, the condition A> B is also satisfied. It is preferable that a is longer than b by at least 20% or more. A is preferably configured to be at least 20% longer than B. As can be seen in FIG. 5, the circulating water flow path 25 can be arranged only in the air electrode cooling plate 28. The electrolyte membrane 20 can be formed using an ion exchange resin.
[0053]
The sectional structure of the fuel cell according to this embodiment is the sectional structure of the fuel cell shown in FIG. 2, the sectional structure of the cell is the sectional structure of the cell shown in FIG. 3, and the stack structure is the stack of the fuel cell shown in FIG. Since the structure conforms to the respective structures, the description is omitted.
[0054]
Hereinafter, functions related to the cooling effect around the unit cell of the fuel cell according to the present embodiment will be described.
[0055]
Since the physical distance b between the circulating water flow path 25 and the air electrode 22 is shorter than the physical distance a between the circulating water flow path 25 and the fuel electrode 21, the air electrode 22 is smaller than the fuel electrode 21. The cooling water is brought into contact with the cooling water at a shorter distance, and the cooling effect of the cooling water is more exerted on the air electrode 22 than on the fuel electrode 21. As a result, it is possible to effectively suppress a temperature rise on the side of the air electrode 22 that generates a large amount of heat.
[0056]
That is, according to the present embodiment, the physical distance b between the circulating water flow path 25 and the air electrode 22 is shorter than the physical distance a between the circulating water flow path 25 and the fuel electrode 21. Thereby, the cooling effect of the cooling water on the air electrode 22 can be higher than the cooling effect on the fuel electrode 21. For this reason, since the temperature rise on the side of the air electrode 22 that generates a larger amount of heat than that on the side of the fuel electrode 21 is suppressed, it is possible to effectively prevent the battery output from decreasing over time when the battery is used.
[0057]
[Third embodiment]
In this embodiment, a circulating water flow path is provided between the air electrode of one unit cell and the fuel electrode of another unit cell. This circulating water flow path is provided from the air electrode. FIG. 6 schematically illustrates the configuration of the fuel cell according to the present embodiment. In the figure, the fuel cell according to the present embodiment includes a plurality of unit cells, a fuel flow path 33, an air flow path 34, a circulating water flow path 35, a gasket 36, an anode cooling plate 37, And a plate 38. The unit cell includes an electrolyte membrane 30 formed of a solid polymer, a fuel electrode 31 disposed on one side of the electrolyte membrane 30, and an air electrode 32 disposed on the other side of the electrolyte membrane 30. .
[0058]
The fuel passage 33 is formed in an anode cooling plate 37 in which the anode 31 is stored. The air passage 34 is formed in an air electrode cooling plate 38 in which the air electrode 32 is stored. A circulating water flow path 35 for cooling the cell is formed at a bonding portion 39 of the fuel electrode cooling plate 37 and the air electrode cooling plate 38. That is, the groove-shaped channel formed in the fuel electrode cooling plate 37 and the groove-shaped water channel formed in the air electrode cooling plate 38 are combined at the bonding portion 39 to form the circulating water channel 35. It has become. Since the water flow path on the air electrode side is formed in a deeper groove than the water flow path on the fuel electrode side, the air electrode 32 comes into contact with the cooling water (water) at a shorter distance than the fuel electrode 31. As a result, the temperature rise of the air electrode 32 is more effectively suppressed than that of the fuel electrode 31.
[0059]
The sectional structure of the fuel cell according to this embodiment is the sectional structure of the fuel cell shown in FIG. 2, the sectional structure of the cell is the sectional structure of the cell shown in FIG. 3, and the stack structure is the stack of the fuel cell shown in FIG. Since the structure conforms to the respective structures, the description is omitted.
[0060]
【The invention's effect】
As described above, according to the fuel cell of the present invention, in the polymer electrolyte fuel cell, the effect of cooling the air electrode by the cooling water can be higher than the effect of cooling the fuel electrode by the cooling water. For this reason, it is possible to suppress a temperature rise on the air electrode side, which generates a larger amount of heat than on the fuel electrode side, and it is possible to effectively suppress a decrease in battery output over time when the battery is used.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a unit cell of a fuel cell according to a first embodiment.
FIG. 2 is a diagram schematically illustrating a cross-sectional structure of a fuel cell using a unit cell according to the first embodiment.
FIG. 3 is a diagram schematically illustrating a detailed cross-sectional structure of a unit cell according to the first embodiment.
FIG. 4 is a diagram schematically showing a configuration of a stack structure of the fuel cell according to the first embodiment.
FIG. 5 is a diagram schematically illustrating a configuration of a fuel cell according to a second embodiment.
FIG. 6 is a diagram schematically showing a configuration of a fuel cell according to a third embodiment.
FIG. 7 is an explanatory diagram for explaining the principle of a conventional general polymer electrolyte fuel cell.
FIG. 8 is a cross-sectional view showing the configuration of a basic unit cell of a conventional general polymer electrolyte fuel cell.
FIG. 9 is a cross-sectional view showing a cell stack configuration in a main body of a conventional general polymer electrolyte fuel cell.
[Explanation of symbols]
Reference Signs List 10 electrolyte membrane, 11 fuel electrode, 12 air electrode, 15 unit cell, 16 diffusion layer, 17 fuel flow path, 18 air flow path, 20 electrolyte membrane, 21 fuel electrode, 22 air electrode, 23 fuel flow path, 24 air flow Road, 25 circulating water flow path, 26 gasket, 27 fuel electrode cooling plate, 28 air electrode cooling plate, 30 electrolyte membrane, 31 fuel electrode, 32 air electrode, 33 fuel flow path, 34 air flow path, 35 circulating water flow path, 36 Gasket, 37 fuel electrode cooling plate, 38 air electrode cooling plate, 39 bonding part, 126 catalyst layer, 130 catalyst layer, 132 gas diffusion layer, 134 separator, 138 gas flow path, 140 gas flow path, 128 gas diffusion layer,
150 unit cells, 151 circulating water flow path.

Claims (8)

A plurality of unit cells each having a fuel electrode on one side of the solid electrolyte membrane and an air electrode on the other side are stacked, and a plurality of unit cells are stacked between the air electrode of one unit cell and the fuel electrode of another adjacent unit cell. A fuel cell having a stack structure in which cooling channels are arranged in
Of the air electrode of the one unit cell and the fuel electrode of the other unit cell, the heat removal capacity of the cooling flow path for one of the electrodes is smaller than the heat removal capacity of the cooling flow path for the other electrode. A fuel cell characterized by being configured to be large. The fuel cell according to claim 1,
The fuel cell according to claim 1, wherein the one electrode has higher thermal conductivity than the other electrode. The fuel cell according to claim 1, wherein
The fuel cell according to claim 1, wherein a thickness of the one electrode is smaller than a thickness of the other electrode. The fuel cell according to any one of claims 1 to 3,
The fuel cell according to claim 1, wherein the one electrode includes a gas diffusion layer containing a good heat conductive filler. The fuel cell according to any one of claims 1 to 4,
A fuel cell, wherein a distance between the one electrode and the cooling channel is shorter than a distance between the other electrode and the cooling channel. The fuel cell according to claim 5,
A cooling plate including the cooling channel is disposed between the one unit cell and the other unit cell, and the cooling plate includes:
A first plate having a flow path for air and a flow path for cooling water adjacent to the one electrode;
It has a structure in which a second plate having a flow path for fuel gas and a flow path for cooling water adjacent to the other electrode is laminated in a state where the surfaces provided with the flow path grooves are in contact with each other. And
A fuel cell, wherein the flow channel of each plate is integrated to form the cooling flow channel. The fuel cell according to any one of claims 1 to 6,
A fuel cell, wherein the one electrode is an air electrode and the other electrode is a fuel electrode. The fuel cell according to any one of claims 1 to 6,
A fuel cell, wherein the one electrode is a fuel electrode and the other electrode is an air electrode.

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