JP2002100369A - Solid high polymer molecule type fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid high polymer molecule type fuel cell which only humidifying from an air electrode side can run. SOLUTION: The solid high polymer molecular type fuel cell 1 is equipped with an electrolyte film 2, which has a high polymer molecule ion exchange component, an air electrode 3, and a fuel electrode 4. The air electrode 3 and the fuel electrodes 4 consist only of the high polymer molecule ion exchange component, and two or more catalyst particles made of carbon black particles of which the surfaces are made to have catalyst metal. In the air electrode 3, the carbon black grains have hydrophilic nature that an amount A of water adsorption under a saturation water vapor pressure in 60 deg.C is A<=80 cc/g, and a ratio of a blend weight Wp of the high polymer molecule ion exchange component and the blend weight Wc of the carbon black grains that are Wp/Wc, is 0.2<=Wp/Wc<=0.8. On the fuel electrode 4, the carbon black grains have the hydrophilic nature that the amount A of water adsorption is A>=150 cc/g, and the above ratio Wp/Wc is 0.6<=Wp/Wc<=1.25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer electrolyte fuel cell, and more particularly, to an electrolyte membrane having a polymer ion exchange component,
The present invention relates to a device having an air electrode and a fuel electrode sandwiching the electrolyte membrane, and humidifying only from the air electrode side.

[0002]

2. Description of the Related Art Conventionally, as the air electrode and the fuel electrode, a polymer ion-exchange component which imparts proton conductivity to both electrodes and functions as a binder, and a plurality of catalyst particles having a catalyst metal supported on the surface of carbon black particles. And PTFE (polytetrafluoroethylene) particles. The PTFE particles have water repellency and have a function of adjusting the water retention of the air electrode and the fuel electrode.

In order to maintain the proton conductivity of the electrolyte membrane while maintaining the electrolyte membrane in a wet state, conventionally, air and hydrogen are humidified and then supplied to the air electrode and the fuel electrode, respectively. Is adopted.

[0004]

However, the use of PTFE particles as a component of the air electrode and the fuel electrode means that the thickness of the air electrode and the fuel electrode is reduced in order to further improve the power generation performance. This has been an obstacle in meeting the requirements of increasing the proton conductivity and keeping the resistance overvoltage low.

Further, according to the conventional humidifying means, the humidifier must be installed by performing a troublesome sealing operation on each of the air supply line and the hydrogen supply line, so that the equipment cost is increased and the structure is complicated. There was a problem of inviting.

[0006]

According to the present invention, the power generation performance can be further improved by reducing the thickness of the air electrode and the fuel electrode, and by providing specific air and fuel electrodes. It is an object of the present invention to provide the polymer electrolyte fuel cell that can be operated only by humidification from the air electrode side.

[0007] To achieve the above object, according to the present invention,
An electrolyte membrane having a polymer ion exchange component, and an air electrode and a fuel electrode sandwiching the electrolyte membrane, wherein the air electrode and the fuel electrode are each composed of a plurality of catalysts having a catalyst metal supported on the surface of carbon black particles. The carbon black particles at the air electrode have a water repellency such that the water adsorption amount A under a saturated steam pressure of 60 ° C. is A ≦ 80 cc / g, and the carbon black particles have a high water repellency. The weight of the molecular ion exchange component
And the blending weight of the carbon black particles is Wc
Where the ratio Wp / Wc of the blending weights Wp and Wc is 0.2 ≦ Wp / Wc ≦ 0.8, and the carbon black particles are adsorbed on the fuel electrode under a saturated steam pressure of 60 ° C. The quantity A is A ≧ 150 cc / g,
When the blend weight of the polymer ion exchange component is Wp and the blend weight of the carbon black particles is Wc, the ratio Wp / Wc of the blend weights Wp and Wc is 0.6 ≦ Wp. Wp / Wc ≦ 1.25,
There is provided a polymer electrolyte fuel cell configured to humidify only from the air electrode side.

[0008] With the above configuration, it is possible to stop the use of PTFE particles by giving the water-repellent carbon black particles and the hydrophilic carbon black particles the function of adjusting the water retention of the air electrode and the fuel electrode, respectively. It is. This is effective in reducing the thickness of the cathode and anode.

When the ratio Wp / Wc of the blending weights Wp and Wc at the air electrode and the fuel electrode is set as described above, the thickness of the air electrode and the fuel electrode is reduced because the PTFE particles are not included. As a result, it is possible to increase proton conductivity and suppress an increase in resistance overvoltage, thereby improving power generation performance.

However, in the air electrode, when the ratio Wp / Wc is less than 0.2, the thickness of the air electrode is further reduced, but the coverage of the catalyst particles is deteriorated and the power generation performance is reduced. On the other hand, when Wp / Wc> 0.8, the flow of the humidifying water becomes worse due to an increase in the thickness of the air electrode. At the fuel electrode, the ratio Wp / Wc is Wp
When /Wc<0.6, water retention deteriorates, while Wp /
When Wc> 1.25, the degree of dispersion of the polymer ion-exchange component deteriorates, so that the thickness of the fuel electrode increases.

Further, since the humidifier needs to be provided only on the air supply pipe side, the equipment cost can be reduced and the structure can be simplified.

In this case, when humidification is performed from the air electrode side, the humidification water smoothly flows into the electrolyte membrane due to the water repellency of the carbon black particles in the air electrode, and the humidification water flows into the electrolyte membrane of the generated water of the air electrode. Is also generated, so that the electrolyte membrane is in a wet state. On the other hand, some of the water in the electrolyte membrane flows into the fuel electrode and is retained there because the carbon black particles of the fuel electrode are hydrophilic. The electrolyte membrane is kept in a wet state by the water holding of the fuel electrode and the humidification of the air electrode. Excess water is discharged outside at the cathode and anode.

However, when the water adsorption amount A of the carbon black particles at the air electrode is A> 80 cc / g, the water repellency decreases and the flow of the humidified water deteriorates. The water adsorption amount A is A <
At 150 cc / g, the hydrophilicity decreases and the water retention becomes insufficient.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a polymer electrolyte fuel cell (cell) 1 includes an electrolyte membrane 2, an air electrode 3 and a fuel electrode 4, which are in close contact with both sides of the electrolyte membrane 2, respectively. It comprises a pair of diffusion layers 5 and 6 which are in close contact with both electrodes 3 and 4, respectively, and a pair of separators 7 and 8 which are in close contact with both diffusion layers 5, 6. In this case, humidification is performed only from the air electrode 3 side. In the embodiment, the electrolyte membrane-electrode assembly 9 includes the electrolyte membrane 2, the air electrode 3, the fuel electrode 4, and both diffusion layers 5 and 6.

The electrolyte membrane 2 is composed of a polymer ion exchange component having proton conductivity, in this embodiment, an aromatic hydrocarbon polymer ion exchange component. The air electrode 3 and the fuel electrode 4 have a plurality of catalyst particles in which a plurality of Pt particles as a catalyst metal are supported on the surface of carbon black particles, and also have a proton conductivity and a function as a binder. Or, it is composed of a different polymer ion exchange component, in this embodiment, an aromatic hydrocarbon polymer ion exchange component, and does not include PTFE particles as the third component.

Each of the diffusion layers 5 and 6 is made of a porous carbon paper or a carbon plate, and each of the separators 7 and 8 is made of graphitized carbon so as to have the same form. 7 multiple grooves 1
0 is supplied with air, and hydrogen is supplied to a plurality of grooves 11 which are present in the separator 8 on the side of the fuel electrode 4 and intersect with the grooves 10.

The aromatic hydrocarbon-based polymer ion-exchange component has the property of being fluorine-free and soluble in a solvent. Table 1 shows this type of polymer ion exchange component.
Various sulfonated aromatic hydrocarbon polymers are used.

[0018]

[Table 1]

As the solvent, various polar solvents listed in Table 2 are used.

[0020]

[Table 2]

At the air electrode 3 on the humidifying side, the carbon black particles are. It has water repellency such that the water adsorption amount A under a saturated steam pressure of 60 ° C. is A ≦ 80 cc / g. In the air electrode 3, when the blending weight of the polymer ion exchange component is Wp and the blending weight of the carbon black particles is Wc, the ratio Wp of the blending weights Wp and Wc is W.
p / Wc is set to 0.2 ≦ Wp / Wc ≦ 0.8.

On the other hand, in the fuel electrode 4, the carbon black particles have hydrophilicity such that the water adsorption amount A at 60 ° C. under a saturated steam pressure is A ≧ 150 cc / g. In the fuel electrode 4, when the blending weight of the polymer ion exchange component is Wp and the blending weight of the carbon black particles is Wc, the ratio Wp / Wc of the blending weights Wp and Wc is obtained.
Wc is set to 0.6 ≦ Wp / Wc ≦ 1.25.

With the above structure, the water-repellent carbon black particles and the hydrophilic carbon black particles have the function of adjusting the water retention of the air electrode 3 and the fuel electrode 4, respectively, so that the use of the PTFE particles is stopped. Is possible. This is effective in reducing the thickness of the cathode 3 and the anode 4.

When the ratio Wp / Wc of the blending weights Wp and Wc in the air electrode 3 and the fuel electrode 4 is set as described above, the thickness of the air electrode 3 and the fuel electrode 4 may be reduced because the PTFE particles may not be contained. In addition, it is possible to increase the proton conductivity and reduce the rise of the resistance overvoltage to improve the power generation performance.

Further, since the humidifier may be provided only on the air supply pipe side, the equipment cost can be reduced and the structure can be simplified.

In this case, when humidification is performed from the air electrode 3 side,
The humidified water flows smoothly into the electrolyte membrane 2 because the carbon black particles of the air electrode 3 are water repellent, and the generated water of the air electrode 3 also diffuses back into the electrolyte membrane 2, so that the electrolyte membrane 2 becomes wet. State. On the other hand, part of the water in the electrolyte membrane 2 flows into the fuel electrode 4 and is retained there because the carbon black particles of the fuel electrode 4 are hydrophilic. The electrolyte membrane 2 is kept in a wet state by the water holding of the fuel electrode 4 and the humidification of the air electrode 3. At the air electrode 3 and the fuel electrode 4, excess water is discharged to the outside.

Hereinafter, a specific example will be described. I- (1) Manufacture of air electrode The amount of water adsorbed at 60 ° C. under a saturated steam pressure is A = 72.
cc / g of water-repellent carbon black particles (trade name:
Vulcan XC-72) supported Pt particles to prepare air electrode catalyst particles. The content of Pt particles in the catalyst particles is 50% by weight. [Example-I] As the aromatic hydrocarbon polymer ion exchange component, the PEEK sulfonate listed in Example 1 in Table 1 was prepared, and this PEEK sulfonate was dissolved under reflux in NMP in Table 2. The content of the PEEK sulfonate in this solution is 6% by weight. In this PEEK sulfonate-containing solution, the ratio Wp / Wc of the blend weight Wp of the PEEK sulfonate to the blend weight Wc of the carbon black particles is Wp.
The catalyst particles were mixed so that /Wc=0.2, and then dispersed using a ball mill to prepare a slurry for an air electrode. This slurry was prepared with a Pt content of 0.5 mg / cm
^The air electrode 3 having a diffusion layer 5 was obtained by applying the coating material to one surface of a plurality of porous carbon papers and drying the coating. This air electrode 3 is referred to as Example 1. [Example-II] The ratio Wp / Wc of the blending weight Wp of the PEEK sulfonated product to the blending weight Wc of the carbon black particles is represented by W
Example-I except that p / Wc = 0.4 was set.
The air electrode 3 having the diffusion layer 5 was obtained in the same manner as described above. This air electrode 3 is referred to as Example 2. [Example-III] Except that the ratio Wp / Wc of the blending weight Wp of the PEEK sulfonated compound to the blending weight Wc of the carbon black particles was set to Wp / Wc = 0.6.
Air electrode 3 having diffusion layer 5 was obtained in the same manner as in I. This air electrode 3 is referred to as Example 3. [Example-IV] The ratio Wp / Wc of the blending weight Wp of the PEEK sulfonated product to the blending weight Wc of the carbon black particles is represented by W
Example-I except that p / Wc = 0.8 was set.
The air electrode 3 having the diffusion layer 5 was obtained in the same manner as described above. This air electrode 3 is referred to as Example 4. [Example-V] The ratio Wp / Wc of the blending weight Wp of the PEEK sulfonated product to the blending weight Wc of the carbon black particles is represented by W
Example-except that p / Wc was set to 1.25
Air electrode 3 having diffusion layer 5 was obtained in the same manner as in I. This air electrode 3 is referred to as Example 5. [Example-VI] The ratio Wp / Wc of the blending weight Wp of the PEEK sulfonated product to the blending weight Wc of the carbon black particles is represented by W
Example-I except that p / Wc = 2.0 was set.
The air electrode 3 having the diffusion layer 5 was obtained in the same manner as described above. This air electrode 3 is referred to as Example 6. I- (2) Manufacture of fuel electrode Water adsorption amount A under saturated steam pressure of 60 ° C. is A = 37.
Pt particles were supported on hydrophilic carbon black particles (trade name: Ketjen Black EC) of 0 cc / g to prepare fuel electrode catalyst particles. The content of Pt particles in the catalyst particles is 50% by weight. [Example-I] As the aromatic hydrocarbon-based polymer ion-exchange component, the PEEK sulfonate listed as Example I in Table 1 was prepared, and this PEEK sulfonate was dissolved in NMP in Table 2 under reflux. The content of the PEEK sulfonate in this solution is 6% by weight. In this PEEK sulfonate-containing solution, the ratio Wp / Wc of the blend weight Wp of the PEEK sulfonate to the blend weight Wc of the carbon black particles is Wp.
The catalyst particles were mixed so that /Wc=0.4, and then dispersed using a ball mill to prepare a slurry for the fuel electrode. This slurry was prepared with a Pt content of 0.5 mg / cm
^The fuel electrode 4 having a diffusion layer 6 was obtained by applying the mixture to one surface of a plurality of porous carbon papers and drying the mixture. This fuel electrode 4 is taken as an example (1). [Example-II] The ratio Wp / Wc of the blending weight Wp of the PEEK sulfonated product to the blending weight Wc of the carbon black particles is represented by W
Example-I except that p / Wc = 0.6 was set.
The fuel electrode 4 having the diffusion layer 6 was obtained in the same manner as described above. This fuel electrode 4 is taken as an example (2). [Example-III] Except that the ratio Wp / Wc of the blending weight Wp of the PEEK sulfonate to the blending weight Wc of the carbon black particles was set to Wp / Wc = 0.8,
Fuel electrode 4 having diffusion layer 6 was obtained in the same manner as in I. This fuel electrode 4 is taken as an example (3). [Example-IV] The ratio Wp / Wc of the blending weight Wp of the PEEK sulfonated product to the blending weight Wc of the carbon black particles is represented by W
Example-except that p / Wc was set to 1.25
Fuel electrode 4 having diffusion layer 6 was obtained in the same manner as in I. This fuel electrode 4 is taken as an example (4). [Example-V] The ratio Wp / Wc of the blending weight Wp of the PEEK sulfonated product to the blending weight Wc of the carbon black particles is represented by W
Example-Except that p / Wc = 1.75 was set.
Fuel electrode 4 having diffusion layer 6 was obtained in the same manner as in I. This fuel electrode 4 is taken as an example (5). II. Table 3 shows examples 1 to 6 of the cathode 3 and examples of the anode 4 (1)
Formulation weight Wp of PEEK sulfonated product related to (5)
And the ratio of the blending weight Wc of the carbon black particles Wp /
The relationship between Wc and water retention is shown. This water retention was calculated from the amount of water adsorbed by the gas adsorber at a saturated steam pressure of 60 ° C.

[0028]

[Table 3]

FIG. 2 is a graph showing the ratio W of both compounding weights based on Table 3.
7 is a graph showing the relationship between p / Wc and the water retention of the air electrode and the fuel electrode. In the figure, Examples 1 to 6 correspond to the air electrode, and Examples (1) to (5) correspond to the fuel electrode. This is the same in the following drawings. From FIG. 2, it can be seen that when the ratio Wp / Wc of the two compounding weights is the same, the air electrode using the water-repellent carbon particles has lower water retention than the fuel electrode using the hydrophilic carbon particles. Further, in the air electrode and the fuel electrode, there is a tendency that the water retention increases as the ratio Wp / Wc of the blended weight increases.

Table 4 shows the ratio Wp / W of the blending weights for Examples 1 to 6 of the cathode 3 and Examples (1) to (5) of the anode 4.
The relationship between c and the thickness of the air electrode 3 and the fuel electrode 4 is shown.

[0031]

[Table 4]

FIG. 3 is a graph showing the ratio W of both compounding weights based on Table 4.
7 is a graph showing the relationship between p / Wc and the thickness of the air electrode and the fuel electrode. FIG. 3 shows that the thicknesses of the air electrode and the fuel electrode increase as the ratio Wp / Wc increases.

Table 5 shows the ratio Wp / W of the blending weights for Examples 1 to 6 of the cathode 3 and Examples (1) to (5) of the anode 4.
The relationship between c and the coverage Cc of the catalyst particles is shown.

[0034]

[Table 5]

The coverage Cc of the catalyst particles is defined as Ae, where Ae is the plane area of the air electrode and the fuel electrode, and Ac is the sum of the areas of a plurality of catalyst particles exposed on the plane of the air electrode and the fuel electrode.
Where Cc = {(Ae−Ac) / Ae} × 100
(%).

FIG. 4 is a graph showing the ratio W of both compounding weights based on Table 5.
7 is a graph showing the relationship between p / Wc and the coverage Cc of catalyst particles. FIG. 4 shows that the coverage Cc of the catalyst particles increases as the ratio Wp / Wc increases.

Table 6 shows the ratio Wp / W of the blending weights for Examples 1 to 6 of the cathode 3 and Examples (1) to (5) of the anode 4.
4 shows the relationship between c and the degree of dispersion D of the catalyst particles.

[0038]

[Table 6]

The degree of dispersion D of the catalyst particles was determined by the following method. First, the theoretical Pt concentration Tp and the PEE in the catalyst particles were determined from the blending amounts of the catalyst particles and the PEEK sulfonate during the production of the air electrode 3 (or the fuel electrode 4).
The theoretical S (sulfur) concentration Ts in the K sulfonate was calculated, and then the theoretical value ratio Ts / Tp was calculated from the theoretical values. Also, the surface of the air electrode 3 etc. was observed with EPMA,
The measured Pt concentration Ap in the catalyst particles and the measured S concentration As in the PEEK sulfonate were determined by surface analysis.
From these measured values, the measured value ratio As / Ap was determined.

Thereafter, the degree of dispersion D is calculated as follows: D = [{(Ts / Tp)-(As / Ap)} / (Ts /
Tp)] × 100 (%).

FIG. 5 shows the ratio W of the blending weights based on Table 6.
4 is a graph showing the relationship between p / Wc and the degree of dispersion D of catalyst particles. FIG. 5 shows that the degree of dispersion D of the catalyst particles increases as the ratio Wp / Wc increases.

Table 7 shows the relationship between the degree of dispersion D of the catalyst particles and the thickness of the cathode 3 and the anode 4 for Examples 1 to 6 of the cathode 3 and Examples (1) to (5) of the anode 4. .

[0043]

[Table 7]

FIG. 6 is a graph showing the relationship between the degree of dispersion D of the catalyst particles and the thickness of the air electrode and the fuel electrode based on Table 7. FIG. 6 shows that the thickness of the air electrode and the fuel electrode increases as the degree of dispersion D of the catalyst particles increases. III. Power generation performance of fuel cell A 50 μm-thick electrolyte membrane 2 was formed using the same PEEK sulfonate used in the production of the air electrode 3 and the fuel electrode 4. In addition, examples 1 to 6 of the cathode 3 and examples (1) to (5) of the anode 4 are prepared.
Performs a combination that makes a round robin with the examples (1) to (5) of the fuel electrode 4. That is, for example 1, example 1 and example (1), example 1 and example (2) ... example By combining 1 and Example (5), 30 electrode pairs were obtained. The electrolyte membrane 2 is formed by each electrode pair, and thus a pair of the cathode 3 and the anode 4.
And hot pressing was performed under the conditions of 140 ° C., 1.5 MPa, and 1 minute to obtain an electrolyte membrane-electrode assembly 9. The polymer electrolyte fuel cell 1 was assembled using each of the electrolyte membrane-electrode assemblies 9 and power was generated under the condition that only the air electrode 3 was humidified to measure the relationship between the current density and the terminal voltage. In this case, the terminal voltage at 0.8 A / cm ^2, which is on the high current density side, was used as a comparison value of the terminal voltage of each battery because the diffusion of water greatly affected the terminal voltage.

Table 8 shows the ratio Wp / W of the blending weights in Examples 1 to 6 of the cathode 3 and Examples (1) to (5) of the anode 4.
c, the combination of the air electrode and the fuel electrode in each battery,
And the terminal voltage at 0.8 A / cm ² .

[0046]

[Table 8]

FIG. 7 shows examples 1 to 3 of the air electrode 3 based on Table 8.
6 is a graph showing a relationship between a combination of Examples (1) to (5) of the fuel cell 6 and the fuel electrode 4 and a terminal voltage. As is clear from Table 8 and FIG. 7, Examples 1 to 4 of the air electrode 3 and the fuel electrode 4
When the polymer electrolyte fuel cell 1 is operated under the condition that the combination is performed between the examples (2) to (4), the humidification is performed only from the air electrode 3 side, the power generation performance can be improved. .

For comparison, in the fuel cell 1 in which the example 3 of the air electrode 3 and the example (3) of the fuel electrode 4 were combined, power generation was performed under the condition that humidification was performed only from the fuel electrode 4 side. When the relationship between the current density and the terminal voltage was measured, it was found that the terminal voltage at a current density of 0.8 A / cm ² was 0.618 V. It is apparent that this terminal voltage is about 10% lower than the terminal voltage of 0.691 V when the example 3 of the air electrode and the example (3) of the fuel electrode in Table 8 are combined.

From this fact, the fuel cell 1 in which the examples 1 to 4 of the air electrode 3 and the examples (2) to (4) of the fuel electrode 4 are combined is performed.
In this case, it is clear that the humidification is performed only from the cathode 3 side.

When the ratio Wp / Wc of the weights of the cathode 3 and the anode 4 is set as described above, the thickness t of the cathode 3 is 3 μm as shown in Examples 1 to 4 from Table 4. ≦ t ≦ 7 μm and the thickness t of the fuel electrode 4
Is 6 μm ≦ t ≦ 8 μm as in Examples (2) to (4), and Table 5 shows that the coverage Cc of the catalyst particles on the air electrode 3 is 72% ≦ Cc ≦ 97 as in Examples 1 to 4. % And the coverage Cc of the catalyst particles at the fuel electrode 4 becomes
As in Examples (2) to (4), 95% ≦ Cc ≦ 98%. Further, from Table 6, the degree of dispersion D of the catalyst particles in the air electrode 3 is 2% ≦ D ≦ 7 as in Examples 1 to 4. %, And the degree of dispersion D of the catalyst particles in the fuel electrode 4 is shown in Examples (2) to
As in (4), 5% ≦ D ≦ 8%.

[0051]

According to the present invention, according to the present invention, it is possible to exhibit high power generation performance even when operated only by humidification from the air electrode side, and it is inexpensive and simple in structure. A polymer electrolyte fuel cell can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a polymer electrolyte fuel cell.

FIG. 2 is a graph showing a relationship between a ratio Wp / Wc of both compounding weights and water retention of an air electrode and a fuel electrode.

FIG. 3 is a graph showing a relationship between a ratio Wp / Wc of both compounding weights and thicknesses of an air electrode and a fuel electrode.

FIG. 4 is a graph showing a relationship between a ratio Wp / Wc of both compounding weights and a coverage Cc of catalyst particles.

FIG. 5 is a graph showing a relationship between a ratio Wp / Wc of both compounding weights and a degree of dispersion D of catalyst particles.

FIG. 6 is a graph showing the relationship between the degree of dispersion D of catalyst particles and the thickness of an air electrode and a fuel electrode.

FIG. 7 is a graph showing a relationship between a combination of an air electrode and a fuel electrode and a terminal voltage.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 solid polymer fuel cell 2 electrolyte membrane 3 air electrode 4 fuel electrode

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Nobuhiro Saito 1-4-1, Chuo, Wako, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Junji Matsuo 1-4-1, Chuo, Wako, Saitama Prefecture No. F-term in Honda R & D Co., Ltd. (reference) 5H018 AA06 AS02 AS03 EE03 EE08 EE17 HH00 HH05 HH08 5H026 AA06 EE02 EE05 EE18 HH00 HH05 HH08

Claims (1)

[Claims] An electrolyte membrane (2) having a polymer ion exchange component, and an air electrode (3) and a fuel electrode (4) sandwiching the electrolyte membrane (2), wherein the air electrode (3) and the fuel The electrode (4) is composed of a plurality of catalyst particles each having a catalyst metal supported on the surface of carbon black particles and a polymer ion exchange component. In the air electrode (3), the carbon black particles have a temperature of 60 ° C. When it has water repellency such that the water adsorption amount A under a saturated steam pressure is A ≦ 80 cc / g, and the compounding weight of the polymer ion exchange component is Wp, and the compounding weight of the carbon black particles is Wc. , Ratio Wp / W of both blending weights Wp, Wc
c is 0.2 ≦ Wp / Wc ≦ 0.8, and at the fuel electrode (4), the carbon black particles are at 60 ° C.
Water adsorption amount A under the saturated steam pressure of A ≧ 150 cc
/ G, and the blending weight of the polymer ion exchange component is Wp, and the blending weight of the carbon black particles is Wc, the ratio Wp / Wc of the blending weights Wp and Wc. Is 0.6 ≦ Wp / Wc ≦ 1.
25, wherein the humidification is performed only from the side of the air electrode (3).