JP2011070984A - Method of manufacturing electrode catalyst layer for fuel cell, and membrane-electrode assembly having the electrode catalyst layer - Google Patents

Method of manufacturing electrode catalyst layer for fuel cell, and membrane-electrode assembly having the electrode catalyst layer Download PDF

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JP2011070984A
JP2011070984A JP2009221934A JP2009221934A JP2011070984A JP 2011070984 A JP2011070984 A JP 2011070984A JP 2009221934 A JP2009221934 A JP 2009221934A JP 2009221934 A JP2009221934 A JP 2009221934A JP 2011070984 A JP2011070984 A JP 2011070984A
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polymer electrolyte
catalyst layer
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Naoko Uehara
直子 上原
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Toppan Inc
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02E60/50Fuel cells
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electrode catalyst layer, which is excellent in proton conductivity and gas diffusiveness, and to provide a membrane-electrode assembly having the electrode catalyst layer. <P>SOLUTION: A method of manufacturing an electrode catalyst layer for a fuel cell, by which an electrode catalyst layer is formed using catalyst ink containing carbon carrying a catalyst, dispersing solvent and polymer electrolyte, is characterized in that the polymer electrolyte in the dispersing solvent is an aggregate having its average particle diameter of no less than 1 μm and no more than 5 μm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、固体高分子型燃料電池膜電極接合体の、電極触媒層の製造方法に関する。   The present invention relates to a method for producing an electrode catalyst layer of a polymer electrolyte fuel cell membrane electrode assembly.

燃料電池は、水素と酸素の電気化学反応から発電する発電機関であり、発電効率が高く、発電時には水のみを排出することから、次世代の電源として期待されている。固体高分子型燃料電池の膜電極接合体は、高分子電解質膜の両面に電極触媒層を接合させた構造である。膜電極接合体の電極触媒層の外側にガス拡散層を配置させ、さらにセパレータで挟んだものが、燃料電池として使用される。   A fuel cell is a power generation engine that generates electricity from an electrochemical reaction between hydrogen and oxygen, has high power generation efficiency, and discharges only water during power generation, and is expected as a next-generation power source. A membrane electrode assembly of a polymer electrolyte fuel cell has a structure in which electrode catalyst layers are bonded to both surfaces of a polymer electrolyte membrane. A fuel cell is used in which a gas diffusion layer is disposed outside the electrode catalyst layer of the membrane electrode assembly and is further sandwiched between separators.

上記の燃料電池において、電気化学反応は電極触媒層中で進行する。電極触媒層は、触媒担持カーボンと高分子電解質を含む層であり、反応ガスと水は電極触媒層の空孔を通じて、プロトンは高分子電解質を通じて移動することで、電気化学反応が進行する。したがって、膜電極接合体の発電性能を高めるには、電極触媒層において上記のガス拡散経路と、プロトン伝導経路が、十分確保されることが必要である。   In the fuel cell, the electrochemical reaction proceeds in the electrode catalyst layer. The electrode catalyst layer is a layer containing catalyst-supporting carbon and a polymer electrolyte, and the reaction gas and water move through the pores of the electrode catalyst layer, and protons move through the polymer electrolyte, whereby the electrochemical reaction proceeds. Therefore, in order to improve the power generation performance of the membrane electrode assembly, it is necessary to sufficiently secure the gas diffusion path and the proton conduction path in the electrode catalyst layer.

膜電極接合体の製造方法は、触媒担持カーボンと、分散溶媒と、高分子質電解質を少なくとも含む触媒インクを用いる方法が知られている。上記方法では、触媒インクを作製し、これを基材上に塗布・溶媒を除去して、基材上に電極触媒層を設けた転写シートを作製し、これを高分子電解質膜上にホットプレスすることで一体化させる。   As a method for producing a membrane / electrode assembly, a method using a catalyst ink containing at least a catalyst-supporting carbon, a dispersion solvent, and a polymer electrolyte is known. In the above method, a catalyst ink is prepared, and this is coated on a substrate and the solvent is removed to prepare a transfer sheet provided with an electrode catalyst layer on the substrate, and this is hot-pressed on the polymer electrolyte membrane. To integrate.

上記の従来の方法で製造された膜電極接合体の電極触媒層では、触媒担持カーボン粒子の表面を高分子電解質の被膜が覆い、これがプロトンの伝導経路となる。分散溶媒は高分子電解質の良溶媒であることが多く、この場合、触媒担持カーボンを覆う高分子電解質の被膜は、同程度の厚みである。そのため、プロトン伝導経路を増加するために、高分子電解質の含有量を増加させると、被膜の厚みが増加してガスと水の拡散経路が塞がれ、起電力が低下してしまうという問題があった。   In the electrode catalyst layer of the membrane electrode assembly produced by the above-described conventional method, the surface of the catalyst-supporting carbon particles is covered with a polymer electrolyte coating, which serves as a proton conduction path. In many cases, the dispersion solvent is a good solvent for the polymer electrolyte. In this case, the coating film of the polymer electrolyte covering the catalyst-supporting carbon has the same thickness. Therefore, if the content of the polymer electrolyte is increased in order to increase the proton conduction path, the thickness of the coating increases, the gas and water diffusion path is blocked, and the electromotive force decreases. there were.

この問題を解決するため、電極触媒層中に高分子電解質の凝集体を混在させた構造を備えた電極触媒層の製造方法が報告されている。例えば、特許文献1では、貧溶媒中に触媒担持カーボンを分散させ、ここに高分子電解質を加えて凝集体を析出させ、凝集体を触媒担持カーボンに付着させる方法が開示されている。また、特許文献2は、触媒担持カーボンにあらかじめ高分子電解質を被覆し、これと貧溶媒中で析出させた高分子電解質の凝集体を混在させる方法が開示されている。   In order to solve this problem, a method for producing an electrode catalyst layer having a structure in which polymer electrolyte aggregates are mixed in the electrode catalyst layer has been reported. For example, Patent Document 1 discloses a method in which catalyst-supported carbon is dispersed in a poor solvent, a polymer electrolyte is added thereto to precipitate aggregates, and the aggregates are attached to the catalyst-supported carbon. Patent Document 2 discloses a method in which a catalyst-supported carbon is coated with a polymer electrolyte in advance, and this is mixed with a polymer electrolyte aggregate precipitated in a poor solvent.

上記の方法で製造された電極触媒層では、高分子電解質の凝集体が触媒担持カーボン間を橋架けし、プロトン伝導経路として機能することができる。同時に、凝集体が適度な大きさであれば触媒層内部の空孔を塞ぐことがないため、反応ガスと水の拡散経路も確保できる。したがって、従来法よりプロトン伝導経路を増加させつつ、ガスと水の拡散経路を確保することができた。   In the electrode catalyst layer produced by the above method, the aggregate of the polymer electrolyte bridges the catalyst-supporting carbon and can function as a proton conduction path. At the same time, if the agglomerates are of an appropriate size, the pores inside the catalyst layer will not be blocked, and a diffusion path for the reaction gas and water can be secured. Therefore, the diffusion path of gas and water could be secured while increasing the proton conduction path compared with the conventional method.

しかしながら、上記の方法のように、高分子電解質が析出するような貧溶媒中に、高分子電解質を直接加える方法では、高分子電解質を加える速度などの条件によって高分子電解質の凝集の程度が変化するため、凝集体の大きさを一定に保つのが困難であり、凝集体の大きさの制御が難しいという問題があった。凝集の程度が大きくなると、電極触媒層中では触媒担持カーボンに比べて大きな凝集体が点在することになる。このような状態になると、触媒担持カーボンと高分子電解質の接点が少なくなり、プロトン伝導性が低下してしまう。また、あらかじめ高分子電解質で被膜した触媒担持カーボンと高分子電解質の凝集体とを、それぞれ用意するのは、工程の数が多くなるという点が望ましくない。   However, in the method of adding a polymer electrolyte directly to a poor solvent in which the polymer electrolyte is deposited as in the above method, the degree of aggregation of the polymer electrolyte varies depending on conditions such as the rate at which the polymer electrolyte is added. Therefore, there is a problem that it is difficult to keep the size of the aggregate constant, and it is difficult to control the size of the aggregate. When the degree of aggregation increases, large aggregates are scattered in the electrode catalyst layer as compared with the catalyst-supported carbon. In such a state, the number of contacts between the catalyst-supporting carbon and the polymer electrolyte decreases, and proton conductivity decreases. In addition, it is not desirable to prepare catalyst-supported carbon and polymer electrolyte aggregates coated with a polymer electrolyte in advance because the number of steps increases.

特開平8−264190号公報JP-A-8-264190 特許第3564975号公報Japanese Patent No. 3564975

本発明は、プロトン伝導性及びガス拡散性に優れた電極触媒層を、高分子電解質の凝集体の大きさを制御しやすい簡便な製造方法で提供することを目的とする。   An object of the present invention is to provide an electrode catalyst layer excellent in proton conductivity and gas diffusibility by a simple production method in which the size of a polymer electrolyte aggregate can be easily controlled.

本発明者は、下記の電極触媒層の製造方法が上記課題を解決することを見出した。   The present inventor has found that the following method for producing an electrode catalyst layer solves the above problems.

請求項1に係る発明は、触媒担持カーボンと、分散溶媒と、高分子電解質とを用いる燃料電池用電極触媒層の製造方法であって、高分子電解質が分散溶媒中において、平均粒子径が1μm以上、5μm以下の凝集体であることを特徴とする、電極触媒層の製造方法とした。   The invention according to claim 1 is a method for producing an electrode catalyst layer for a fuel cell using a catalyst-supporting carbon, a dispersion solvent, and a polymer electrolyte, wherein the polymer electrolyte is in a dispersion solvent and the average particle diameter is 1 μm. The method for producing an electrode catalyst layer is characterized by being an aggregate of 5 μm or less.

請求項2に係る発明は、触媒担持カーボンの触媒の粒径は、0.5nm以上20nm以下であることを特徴とする、請求項1に記載の電極触媒層の製造方法とした。   The invention according to claim 2 is the method for producing an electrode catalyst layer according to claim 1, wherein the catalyst-supported carbon has a catalyst particle size of 0.5 nm or more and 20 nm or less.

請求項3に係る発明は、触媒担持カーボンの、触媒を担持するためのカーボン粒子の粒径は、10nm以上1000nm以下であることを特徴とする、請求項1または2に記載の電極触媒層の製造方法とした。   The invention according to claim 3 is characterized in that the particle diameter of the carbon particles for supporting the catalyst of the catalyst-supporting carbon is 10 nm or more and 1000 nm or less. It was set as the manufacturing method.

請求項4に係る発明は、分散溶媒に占める溶媒の重量比は、5%以上55%以下であることを特徴とする、請求項1乃至3のいずれかに記載の電極触媒層の製造方法とした。   The invention according to claim 4 is characterized in that the weight ratio of the solvent to the dispersion solvent is 5% or more and 55% or less, and the method for producing an electrode catalyst layer according to any one of claims 1 to 3, did.

請求項5に係る発明は、分散溶媒は、1種の溶媒または2種以上からなる混合溶媒であることを特徴とする、請求項1乃至4のいずれかに記載の電極触媒層の製造方法とした。   The invention according to claim 5 is the method for producing an electrode catalyst layer according to any one of claims 1 to 4, wherein the dispersion solvent is one kind of solvent or a mixed solvent composed of two or more kinds. did.

請求項6に係る発明は、分散溶媒は、酢酸エチル、酢酸ブチル、酢酸イソブチル、酢酸、エチレングリコールモノメチルエーテル、またはエチレングリコールモノエチルエーテルから選択される1種または2種以上を含む混合溶媒であることを特徴とする請求項5に記載の燃料電池用電極触媒層の製造方法とした。   In the invention according to claim 6, the dispersion solvent is a mixed solvent containing one or more selected from ethyl acetate, butyl acetate, isobutyl acetate, acetic acid, ethylene glycol monomethyl ether, or ethylene glycol monoethyl ether. The method for producing a fuel cell electrode catalyst layer according to claim 5.

請求項7に係る発明は、請求項1乃至6のいずれかに記載の電極触媒層の製造方法であって、触媒担持カーボンと、分散溶媒と、高分子電解質とを混合し、分散処理を加える工程を含むことを特徴とする、電極触媒層の製造方法とした。   The invention according to claim 7 is the method for producing an electrode catalyst layer according to any one of claims 1 to 6, wherein the catalyst-supporting carbon, the dispersion solvent, and the polymer electrolyte are mixed and subjected to a dispersion treatment. It was set as the manufacturing method of the electrode catalyst layer characterized by including a process.

請求項8に係る発明は、請求項1乃至7のいずれかに記載の製造方法で製造される電極触媒層を有することを特徴とする膜電極接合体とした。   The invention according to claim 8 is a membrane electrode assembly comprising an electrode catalyst layer produced by the production method according to any one of claims 1 to 7.

請求項9に係る発明は、触媒担持カーボンと、分散溶媒と、高分子電解質とを含有する触媒インクであって、分散溶媒中において高分子電解質は平均粒子径が1μm以上5μm以下の凝集体であることを特徴とする触媒インクとした。   The invention according to claim 9 is a catalyst ink containing a catalyst-supporting carbon, a dispersion solvent, and a polymer electrolyte, wherein the polymer electrolyte is an aggregate having an average particle diameter of 1 μm to 5 μm in the dispersion solvent. It was set as the catalyst ink characterized by a certain thing.

請求項10に係る発明は、分散溶媒は、1種または2種以上からなる混合溶媒であることを特徴とする請求項9に記載の触媒インクとした。   The invention according to claim 10 provides the catalyst ink according to claim 9, wherein the dispersion solvent is a mixed solvent of one kind or two or more kinds.

請求項11に係る発明は、分散溶媒は、酢酸エチル、酢酸ブチル、酢酸イソブチル、酢酸、エチレングリコールモノメチルエーテル、またはエチレングリコールモノエチルエーテルから選択される1種または2種以上を含む混合溶媒であることを特徴とする請求項10に記載の触媒インクとした。   In the invention according to claim 11, the dispersion solvent is a mixed solvent containing one or more selected from ethyl acetate, butyl acetate, isobutyl acetate, acetic acid, ethylene glycol monomethyl ether, or ethylene glycol monoethyl ether. The catalyst ink according to claim 10.

上記の方法によれば、高分子電解質に対して適度な貧溶媒となる分散溶媒を用いることで、高分子電解質が凝集体となる。その平均粒子径が上記1μm以上、5μm以下の範囲に観測される場合は、高分子電解質はある程度の柔らかさ、大きさに凝集した状態となる。高分子電解質がこの状態で、触媒担持カーボンと混合して分散処理を加えると、凝集体の一部が触媒担持カーボンに付着し、その他の部分は触媒担持カーボン間の橋架けの状態となるため、これによりプロトン伝導経路を増加させることができる。   According to said method, a polymer electrolyte becomes an aggregate by using the dispersion | distribution solvent used as a moderate poor solvent with respect to a polymer electrolyte. When the average particle diameter is observed in the range of 1 μm or more and 5 μm or less, the polymer electrolyte is aggregated to a certain degree of softness and size. When the polymer electrolyte is mixed with the catalyst-supported carbon in this state and dispersed, a part of the aggregate adheres to the catalyst-supported carbon, and the other part bridges the catalyst-supported carbon. This can increase the proton conduction path.

本方法は、高分子電解質の平均粒子径が上記範囲であれば、高分子電解質が偏在することはない。また、分散溶媒への高分子電解質の凝集状態を把握していれば、これらを混合し分散処理するのみで良く、簡便に高分子電解質の形態を制御できる方法である。上記の触媒インクを用いれば、反応ガスと水の拡散経路を塞ぐことなくプロトン伝導経路を増加でき、発電性能の高い膜電極接合体を得ることができる。   In this method, as long as the average particle diameter of the polymer electrolyte is within the above range, the polymer electrolyte is not unevenly distributed. Further, if the state of aggregation of the polymer electrolyte in the dispersion solvent is known, it is only necessary to mix and disperse them, and this is a method that can easily control the form of the polymer electrolyte. If the above catalyst ink is used, the proton conduction path can be increased without blocking the diffusion path of the reaction gas and water, and a membrane electrode assembly with high power generation performance can be obtained.

図1Aは本発明の電極触媒層の模式図である。FIG. 1A is a schematic view of an electrode catalyst layer of the present invention. 図1Bは凝集体を混在させた電極触媒層の模式図である。FIG. 1B is a schematic view of an electrode catalyst layer in which aggregates are mixed. 図1Cは大きな凝集体が混在した電極触媒層の模式図である。FIG. 1C is a schematic view of an electrode catalyst layer in which large aggregates are mixed. 図1Dは従来の電極触媒層の模式図である。FIG. 1D is a schematic view of a conventional electrode catalyst layer. 図2は本発明の実施例と比較例のデータをまとめた表である。FIG. 2 is a table summarizing data of examples and comparative examples of the present invention.

以下に、本発明の電極触媒層、電極触媒層の製造方法について説明する。   Below, the manufacturing method of the electrode catalyst layer of this invention and an electrode catalyst layer is demonstrated.

電極触媒層の構造について、図1A乃至図1Dを参照して説明する。電極触媒層は触媒担持カーボンおよび高分子電解質からなり、触媒インクを基材に塗布・乾燥することで製造される。図1A乃至図1Dには、電極触媒層の模式図を示した。電極触媒層は、触媒物質11をカーボン12上に担持した、触媒担持カーボン1、および高分子電解質21、22から構成され、これらの隙間である空孔を通って反応ガスと水が拡散する。   The structure of the electrode catalyst layer will be described with reference to FIGS. 1A to 1D. The electrode catalyst layer is made of a catalyst-supporting carbon and a polymer electrolyte, and is manufactured by applying and drying a catalyst ink on a substrate. 1A to 1D are schematic views of the electrode catalyst layer. The electrode catalyst layer is composed of the catalyst-supporting carbon 1 in which the catalyst substance 11 is supported on the carbon 12 and the polymer electrolytes 21 and 22, and the reaction gas and water diffuse through the pores that are gaps therebetween.

図1Dには従来の製造方法で製造した電極触媒層の模式図を示した。従来の製造方法で製造した触媒インクは、分散溶媒に高分子電解質の良溶媒を用いることが多く、高分子電解質の被膜21が触媒担持カーボン1を、同程度の厚みで被覆する構造であった。プロトンの伝導経路はある程度確保されるが、プロトンの伝導経路をさらに拡大するため、触媒担持カーボンに対する高分子電解質の添加量を増加させると、高分子電解質の被膜21の厚みが増加する。高分子電解質の被膜21の厚みが増加すると反応ガスと水の拡散経路が塞がれてしまい、発電性能が低下する。発電性能の低下は特に拡散性が重要となる高負荷側で影響が大きくなる。   FIG. 1D shows a schematic diagram of an electrode catalyst layer produced by a conventional production method. The catalyst ink produced by the conventional production method often uses a polymer electrolyte good solvent as a dispersion solvent, and the polymer electrolyte coating 21 has a structure in which the catalyst-supporting carbon 1 is coated with the same thickness. . Although the proton conduction path is secured to some extent, when the amount of the polymer electrolyte added to the catalyst-supporting carbon is increased to further expand the proton conduction path, the thickness of the polymer electrolyte coating 21 increases. When the thickness of the polymer electrolyte coating 21 increases, the diffusion path of the reaction gas and water is blocked, and the power generation performance decreases. The decline in power generation performance is particularly significant on the high load side where diffusibility is important.

図1Bには、高分子電解質の凝集体22を混在させた電極触媒層の模式図を示した。高分子電解質の凝集体22は、貧溶媒中で析出させることで製造され、あらかじめ高分子電解質の被膜21で被覆させた触媒担持カーボン1と混在させる。このような構造では、高分子電解質の凝集体22を通じて触媒担持カーボン間でプロトンが伝導できる。凝集体22が触媒担持カーボンの空孔を塞ぐことのない大きさであれば、反応ガスと水の拡散経路を確保しつつ、プロトン伝導経路を増加させることができる。   FIG. 1B shows a schematic diagram of an electrode catalyst layer in which polymer electrolyte aggregates 22 are mixed. The polymer electrolyte aggregate 22 is produced by precipitation in a poor solvent, and is mixed with the catalyst-supporting carbon 1 previously coated with the polymer electrolyte coating 21. In such a structure, protons can be conducted between the catalyst-carrying carbons through the polymer electrolyte aggregate 22. If the aggregate 22 has a size that does not block the pores of the catalyst-carrying carbon, the proton conduction path can be increased while ensuring the diffusion path of the reaction gas and water.

しかしながら、図1Bの構造を備えた電極触媒層を製造する工程で、高分子電解質の凝集体22の大きさが制御できない場合は、図1Cに示すように、高分子電解質の凝集体22が触媒担持カーボン1に対して大きすぎる構造となることがある。このような構造では、高分子電解質は電極触媒層一部に偏在し、触媒担持カーボンの一部にしか接触できないため、プロトン伝導経路が少なくなってしまう。高分子電解質を、硬い凝集体として析出するように貧溶媒中に高分子電解質を直接加える方法では、高分子電解質を加える速度などの条件によって高分子電解質の凝集の程度が変化しやすいため、凝集体の大きさを制御するのが難しいという問題があった。   However, when the size of the polymer electrolyte aggregate 22 cannot be controlled in the process of manufacturing the electrode catalyst layer having the structure of FIG. 1B, the polymer electrolyte aggregate 22 is not a catalyst as shown in FIG. 1C. The structure may be too large for the supported carbon 1. In such a structure, the polymer electrolyte is unevenly distributed in a part of the electrode catalyst layer and can contact only a part of the catalyst-supporting carbon, so that the proton conduction path is reduced. In the method in which the polymer electrolyte is directly added to the poor solvent so that the polymer electrolyte is precipitated as a hard aggregate, the degree of aggregation of the polymer electrolyte is likely to change depending on the conditions such as the rate at which the polymer electrolyte is added. There was a problem that it was difficult to control the size of the aggregate.

図1Aは本発明の電極触媒層の模式図である。本発明の電極触媒層では、高分子電解質は、高分子電解質の被膜21と、被膜21と連続した部分であって橋架け状の高分子電解質23とを含んでいる。この構造を備えた電極触媒層では、高分子電解質の被膜21と、橋架け状の高分子電解質23を通じて十分なプロトン伝導経路を備え、同時に反応ガスと水の拡散経路も確保することができる。また、本発明の電極触媒層は、以下に説明する触媒インクを用いることで、制御が容易な方法で製造することができる。   FIG. 1A is a schematic view of an electrode catalyst layer of the present invention. In the electrode catalyst layer of the present invention, the polymer electrolyte includes a polymer electrolyte coating 21 and a bridge-shaped polymer electrolyte 23 that is a continuous portion of the coating 21. In the electrode catalyst layer having this structure, a sufficient proton conduction path is provided through the polymer electrolyte coating 21 and the bridged polymer electrolyte 23, and at the same time, a diffusion path of the reaction gas and water can be secured. Further, the electrode catalyst layer of the present invention can be produced by a method that is easy to control by using the catalyst ink described below.

本発明の触媒インクは、少なくとも触媒物質を担持した触媒担持カーボン、高分子電解質、および分散溶媒を含有する。   The catalyst ink of the present invention contains at least catalyst-carrying carbon carrying a catalyst substance, a polymer electrolyte, and a dispersion solvent.

本発明の触媒インクに含まれる高分子電解質としては、プロトン伝導性を有するものであれば良く、フッ素系高分子電解質、炭化水素系高分子電解質を用いてもよい。中でも、フッ素系高分子電解質としてDupont社製Nafion(登録商標)、旭硝子(株)社製のフレミオン(登録商標)系材料を好適に用いてもよい。   The polymer electrolyte contained in the catalyst ink of the present invention may be any one having proton conductivity, and may be a fluorine-based polymer electrolyte or a hydrocarbon-based polymer electrolyte. Among these, Nafion (registered trademark) manufactured by Dupont and Flemion (registered trademark) material manufactured by Asahi Glass Co., Ltd. may be suitably used as the fluorine-based polymer electrolyte.

分散溶媒としては、高分子電解質に対して貧溶媒であり、高分子電解質と分散溶媒とを混合したとき、高分子電解質の凝集体の粒度が1μm以上5μm以下の範囲に観測されるものを用いる。ここで、高分子電解質の粒子径は、光回折式粒度分布測定にて観測される平均粒子径を目安にしてもよい。光回折式粒度分布測定で得られる平均粒子径は、実際の粒子径と同一でないものと考えられるが、この粒子径を凝集の程度の目安とすることができる。高分子電解質の凝集体の粒度が1μmより小さいと、図1Dの構造に近い構造となるため、反応ガスと水の拡散経路を十分に確保できなくなり、高分子電解質の凝集体の粒度が5μmより大きいと、図1Cの構造と近い構造となるため、プロトン伝導経路を十分に確保できなくなる。従って、上記の範囲であれば、高分子電解質は分散溶媒中で適度な柔らかさ、大きさの凝集体となっており、触媒担持カーボンと混合して分散処理を加えると、その一部が被膜状21となり触媒担持カーボン上へ付着し、残りの部分は橋架け状の部分23となることにより、図1Aに示す形態の高分子電解質を得ることができる。   The dispersion solvent is a poor solvent for the polymer electrolyte, and when the polymer electrolyte and the dispersion solvent are mixed, one in which the aggregate particle size of the polymer electrolyte is observed in the range of 1 μm to 5 μm is used. . Here, the particle diameter of the polymer electrolyte may be based on the average particle diameter observed in the light diffraction particle size distribution measurement. Although the average particle size obtained by the light diffraction particle size distribution measurement is considered not to be the same as the actual particle size, this particle size can be used as a measure of the degree of aggregation. When the particle size of the polymer electrolyte aggregate is smaller than 1 μm, a structure close to that shown in FIG. 1D is obtained, so that a sufficient diffusion path for the reaction gas and water cannot be ensured. If it is large, the structure is close to that of FIG. 1C, and therefore a sufficient proton conduction path cannot be secured. Therefore, within the above range, the polymer electrolyte is an aggregate of moderate softness and size in the dispersion solvent. When mixed with the catalyst-supporting carbon and subjected to dispersion treatment, a part of the polymer electrolyte is coated. A polymer electrolyte having the form shown in FIG. 1A can be obtained by forming a shape 21 and adhering onto the catalyst-supporting carbon, and the remaining portion becomes a bridge-shaped portion 23.

分散溶媒は上記の範囲を満たすものであれば、1種類でも良く、2種類以上の混合溶媒も用いてもよい。但し、混合溶媒とする場合は、溶媒同士が分離しない構成にする必要がある。溶媒が複数の層に分離してしまうと、電極触媒層とした場合触媒担持カーボンと高分子電解質が分離してしまう可能性があり、図1Aに示す構造が得られない。   As long as the dispersion solvent satisfies the above range, one kind of solvent may be used, or two or more kinds of mixed solvents may be used. However, in the case of using a mixed solvent, it is necessary that the solvent is not separated. If the solvent is separated into a plurality of layers, the catalyst-supporting carbon and the polymer electrolyte may be separated when the electrode catalyst layer is used, and the structure shown in FIG. 1A cannot be obtained.

分散溶媒には、水、及び各種有機溶媒を用いてもよい。なお、フッ素系の高分子電解質を用いる場合は、アルコール類は良溶媒となるため、アルコールのみでは目的の粒度とすることはできない。アルコールに適当な貧溶媒を混合することにより、上記の分散溶媒として用いてもよい。   Water and various organic solvents may be used as the dispersion solvent. In addition, when using a fluorine-type polymer electrolyte, since alcohol becomes a good solvent, it cannot be made the target particle size only with alcohol. You may use it as said dispersion | distribution solvent by mixing a suitable poor solvent with alcohol.

アルコール類としては、例えば、メタノール、エタノール、1−プロパノール、2−プロパノール、1−ブタノール、2−ブタノール、イソブチルアルコール、tert−ブチルアルコール等のアルコール類を用いてもよい。   As alcohols, for example, alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, and tert-butyl alcohol may be used.

貧溶媒となる溶媒としては、例えば、アセトン、メチルエチルケトン、メチルプロピルケトン、メチルブチルケトン、メチルイゾブチルケトン、メチルアミルケトン、ペンタノン、へプタノン、シクロヘキサノン、メチルシクロヘキサノン、アセトニルアセトン、ジエチルケトン、ジプロピルケトン、ジイソブチルケトンなどのケトン類、テトラヒドロフラン、テトラヒドロピラン、ジオキサン、ジエチレングリコールジメチルエーテル、アニソール、メトキシトルエン、ジエチルエーテル、ジプロピルエーテル、ジブチルエーテル等のエーテル類、イソプロピルアミン、ブチルアミン、イソブチルアミン、シクロヘキシルアミン、ジエチルアミン、アニリンなどのアミン類、蟻酸プロピル、蟻酸イソブチル、蟻酸アミル、酢酸メチル、酢酸エチル、酢酸プロピル、酢酸ブチル、酢酸イソブチル、酢酸ペンチル、酢酸イソペンチル、プロピオン酸メチル、プロピオン酸エチル、プロピオン酸ブチルなどのエステル類、その他酢酸、プロピオン酸、ジメチルホルムアミド、ジメチルアセトアミド、N−メチルピロリドン等を用いてもよい。また、グリコール、グリコールエーテル系の溶媒は、一種でも使用できるものもあるが、混合条件によっては他の溶媒と混合溶媒として用いてもよい。グリコール、グリコールエーテル系溶媒としては、エチレングリコール、ジエチレングリコール、プロピレングリコール、エチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル、エチレングリコールジメチルエーテル、エチレングリコールジエチルエーテル、ジアセトンアルコール、1−メトキシ−2−プロパノール、1−エトキシ−2−プロパノール等を使用してもよい。   Examples of the poor solvent include acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl amyl ketone, pentanone, heptanone, cyclohexanone, methyl cyclohexanone, acetonyl acetone, diethyl ketone, dipropyl. Ketones such as ketone and diisobutylketone, tetrahydrofuran, tetrahydropyran, dioxane, diethylene glycol dimethyl ether, anisole, methoxytoluene, diethyl ether, dipropyl ether, dibutyl ether and other ethers, isopropylamine, butylamine, isobutylamine, cyclohexylamine, diethylamine , Amines such as aniline, propyl formate, isobutyl formate, amyl formate, methyl acetate, acetic acid Esters such as chill, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, isopentyl acetate, methyl propionate, ethyl propionate, butyl propionate, and other acetic acid, propionic acid, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. May be used. In addition, some glycol and glycol ether solvents can be used, but depending on the mixing conditions, they may be used as a mixed solvent with other solvents. Glycol and glycol ether solvents include ethylene glycol, diethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diacetone alcohol, 1-methoxy-2-propanol, 1 -Ethoxy-2-propanol or the like may be used.

分散溶媒に占める貧溶媒の重量比は、貧溶媒の種類によっても影響されるが、5%以上55%以下であることが好ましい。分散溶媒に占める貧溶媒の重量比を5%以上55%以下にすることによって、所望の平均粒子径の高分子電解質の凝集体を作ることができる。   The weight ratio of the poor solvent to the dispersion solvent is influenced by the kind of the poor solvent, but is preferably 5% or more and 55% or less. By setting the weight ratio of the poor solvent in the dispersion solvent to 5% or more and 55% or less, a polymer electrolyte aggregate having a desired average particle diameter can be produced.

触媒インク中の固形分含有量は、上記の条件を満たす範囲で変更できるが、多すぎると乾燥工程の後に電極触媒層表面にクラックが入りやすくなり、また逆に少なすぎると所定の厚みまで膜を作製する時間が非常に遅く、生産性が低下してしまうため、1質量%以上50質量%以下であることが好ましい。   The solid content in the catalyst ink can be changed within the range satisfying the above conditions. However, if it is too much, the electrode catalyst layer surface is likely to crack after the drying step, and conversely if it is too little, the film has a predetermined thickness. It is preferable that the amount is 1% by mass or more and 50% by mass or less because the production time is very slow and the productivity is lowered.

本発明で用いる触媒担持カーボンの触媒としては、白金やパラジウム、ルテニウム、イリジウム、ロジウム、オスミウムの白金族元素の他、鉄、鉛、銅、クロム、コバルト、ニッケル、マンガン、バナジウム、モリブデン、ガリウム、アルミニウムなどの金属又はこれらの合金、または酸化物、複酸化物等を使用してもよい。また、これらの触媒の粒径は、大きすぎると触媒の活性が低下し、小さすぎると触媒の安定性が低下するため、0.5nm以上20nm以下が好ましい。更に好ましくは、1nm以上5nm以下が良い。   The catalyst-supported carbon catalyst used in the present invention includes platinum group elements such as platinum, palladium, ruthenium, iridium, rhodium, and osmium, iron, lead, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, A metal such as aluminum or an alloy thereof, an oxide, a double oxide, or the like may be used. Moreover, since the activity of a catalyst will fall when the particle size of these catalysts is too large, and stability of a catalyst will fall when too small, 0.5 nm or more and 20 nm or less are preferable. More preferably, it is 1 nm or more and 5 nm or less.

触媒を担持するためのカーボン粒子の種類は、微粒子状で導電性を有し、触媒におかされないものであればどのようなものでも構わないが、カーボンブラックやグラファイト、黒鉛、活性炭、カーボンファイバー、カーボンナノチューブ、フラーレンを使用してもよい。カーボン粒子の粒径は、小さすぎると電子伝導パスが形成されにくくなり、また大きすぎると電極触媒層のガス拡散性が低下したり、触媒の利用率が低下したりするので、10nm以上1000nm以下程度が好ましい。更に好ましくは、10nm以上100nm以下が良い。   The type of carbon particles for supporting the catalyst may be any particle as long as it is in the form of fine particles and has electrical conductivity and is not affected by the catalyst. Carbon black, graphite, graphite, activated carbon, carbon fiber, Carbon nanotubes and fullerenes may be used. If the particle size of the carbon particles is too small, it becomes difficult to form an electron conduction path. If the particle size is too large, the gas diffusibility of the electrode catalyst layer decreases or the utilization factor of the catalyst decreases. The degree is preferred. More preferably, it is 10 nm or more and 100 nm or less.

本発明の触媒インクは、触媒担持カーボン、高分子電解質、分散溶媒を混合し、分散処理を加えることで得られる。高分子電解質が分散溶媒中で適度な硬さ、大きさの凝集体となっており、これと触媒担持カーボンを接触させて分散処理を加えると、高分子電解質は一部が触媒担持カーボンを被覆し、一部は触媒担持カーボン間の橋架け状の形態をとることができる。分散処理の方法としては、ボールミルやビーズミル、ロールミル、せん断ミル、湿式ミル、超音波分散処理、ホモジナイザーなどが挙げられる。   The catalyst ink of the present invention can be obtained by mixing a catalyst-supporting carbon, a polymer electrolyte, and a dispersion solvent and applying a dispersion treatment. The polymer electrolyte is an agglomerate of appropriate hardness and size in the dispersion solvent. When the catalyst-supported carbon is brought into contact with the polymer electrolyte and dispersed, the polymer electrolyte partially covers the catalyst-supported carbon. However, some of them can take the form of bridges between the catalyst-supporting carbons. Examples of the dispersion treatment method include a ball mill, a bead mill, a roll mill, a shear mill, a wet mill, an ultrasonic dispersion treatment, and a homogenizer.

分散後の触媒インクを基材へ塗布し、乾燥することで、電極触媒層を作製する。塗布に用いる基材には、ガス拡散層のほかに転写フィルムを用いてもよい。転写フィルムとしては、転写性がよい材質であればよく、例えばエチレンテトラフルオロエチレン共重合体(ETFE)、テトラフルオロエチレン−ヘキサフルオロプロピレン共重合体(FEP)、テトラフルオロパーフルオロアルキルビニルエーテル共重合体(PFA)、ポリテトラフルオロエチレン(PTFE)などのフッ素系樹脂を用いてもよい。また、ポリイミド、ポリエチレンテレフタラート、ポリアミド(ナイロン)、ポリサルホン、ポリエーテルサルホン、ポリフェニレンサルファイド、ポリエーテル・エーテルケトン、ポリエーテルイミド、ポリアリレート、ポリエチレンナフタレートなどの高分子フィルムを用いてもよい。これらの基材に、離形層などの処理をしたものを用いても良い。   The dispersed catalyst ink is applied to a substrate and dried to produce an electrode catalyst layer. In addition to the gas diffusion layer, a transfer film may be used as the substrate used for coating. The transfer film may be made of any material having good transferability, such as ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer. Fluorine resins such as (PFA) and polytetrafluoroethylene (PTFE) may be used. Further, a polymer film such as polyimide, polyethylene terephthalate, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, polyethylene naphthalate may be used. You may use what processed the release layer etc. to these base materials.

また、ガス拡散層としては、通常の燃料電池に用いられているものを用いてもよい。具体的にはガス拡散層としてはカーボンクロス、カーボンペーパー、不織布などのポーラスカーボン材を用いてもよい。ガス拡散層は基材として用いてもよい。   Moreover, as a gas diffusion layer, you may use what is used for the normal fuel cell. Specifically, a porous carbon material such as carbon cloth, carbon paper, and nonwoven fabric may be used as the gas diffusion layer. The gas diffusion layer may be used as a substrate.

触媒インクの塗布方法としては、ドクターブレード法、スクリーン印刷法、ロールコーティング法、スプレー法などを用いてもよい。   As a method for applying the catalyst ink, a doctor blade method, a screen printing method, a roll coating method, a spray method, or the like may be used.

基材上に形成した電極触媒層を、高分子電解質膜の両面に接合させることで、膜電極接合体を得ることができる。接合方法は、高分子電解質膜の両面に、基材上に形成した電極触媒層を配置し、これらを加熱、加圧することで接合できる。基材として転写フィルムを用いた場合には、接合後に転写フィルムを剥離し、高分子電解質膜の両面に触媒層を備える膜電極接合体としてもよい。また、基材にガス拡散層を用いた場合には、転写工程後にガス拡散層である基材を剥離する必要は無い。   A membrane / electrode assembly can be obtained by bonding the electrode catalyst layer formed on the substrate to both surfaces of the polymer electrolyte membrane. As a joining method, electrode catalyst layers formed on a base material are arranged on both surfaces of a polymer electrolyte membrane, and these can be joined by heating and pressurizing them. When a transfer film is used as the substrate, the transfer film may be peeled off after bonding, and a membrane electrode assembly including catalyst layers on both sides of the polymer electrolyte membrane may be used. Moreover, when a gas diffusion layer is used for the base material, it is not necessary to peel off the base material that is the gas diffusion layer after the transfer step.

本発明の膜電極接合体に用いられる高分子電解質膜としては、プロトン伝導性を有するものであればよく、フッ素系高分子電解質、炭化水素系高分子電解質を用いてもよい。フッ素系高分子電解質としては、例えば、Dupont社製Nafion(登録商標)、旭硝子(株)製Flemion(登録商標)、旭化成(株)製AcipleNx(登録商標)、Gore社製Gore Select(登録商標)などを用いてもよい。炭化水素系高分子電解質膜としては、スルホン化ポリエーテルケトン、スルホン化ポリエーテルスルホン、スルホン化ポリエーテルエーテルスルホン、スルホン化ポリスルフィド、スルホン化ポリフェニレン等の電解質膜を用いてもよい。中でも、高分子電解質膜としてDupont社製Nafion(登録商標)系材料を好適に用いることができる。   The polymer electrolyte membrane used in the membrane electrode assembly of the present invention may be any one having proton conductivity, and may be a fluorine-based polymer electrolyte or a hydrocarbon-based polymer electrolyte. Fluoropolymer electrolytes include, for example, Dupont Nafion (registered trademark), Asahi Glass Co., Ltd. Flemion (registered trademark), Asahi Kasei Corporation Nile (registered trademark), Gore Corporation Gore Select (registered trademark). Etc. may be used. As the hydrocarbon polymer electrolyte membrane, electrolyte membranes such as sulfonated polyether ketone, sulfonated polyethersulfone, sulfonated polyetherethersulfone, sulfonated polysulfide, and sulfonated polyphenylene may be used. Among them, a Nafion (registered trademark) material manufactured by Dupont can be suitably used as the polymer electrolyte membrane.

(実施例および比較例)
〈触媒インクの調製〉
白金担持量が30質量%である白金担持カーボン触媒(担体:Ketjen)と、20質量%高分子電解質溶液(Dupont社製 Nafion(登録商標))と、分散溶媒とを用意し、遊星型ボールミルで分散処理をおこなった。分散溶媒は、水、エタノール、および下記の溶媒3の三種の混合溶媒とし、溶媒3はナフィオンに対して貧溶媒となるものとした。後述する高分子電解質の凝集体の平均粒子径の測定結果を鑑みて、比較例1は、貧溶媒の添加比を多くして、高分子電解質の凝集体の粒度を高めた構成とし、比較例2は、溶媒3を加えず凝集体を生成しない構成とした。各実施例および比較例における、溶媒3の種類と、分散溶媒に占めるその重量比は以下に示すとおりとした。
実施例1 ・・・ 溶媒3:酢酸ブチル、30%
実施例2 ・・・ 溶媒3:酢酸ブチル、17%
実施例3 ・・・ 溶媒3:酢酸、13%
実施例4 ・・・ 溶媒3:テトラヒドロフラン、10%
比較例1 ・・・ 溶媒3:酢酸ブチル、60%
比較例2 ・・・ 溶媒3:なし
(Examples and Comparative Examples)
<Preparation of catalyst ink>
A platinum-supported carbon catalyst (support: Ketjen) having a platinum support amount of 30% by mass, a 20% by mass polymer electrolyte solution (Dupont Nafion (registered trademark)), and a dispersion solvent were prepared. Distributed processing was performed. The dispersion solvent was three mixed solvents of water, ethanol, and the following solvent 3, and the solvent 3 was a poor solvent for Nafion. In view of the measurement result of the average particle diameter of the polymer electrolyte aggregates described later, Comparative Example 1 has a constitution in which the addition ratio of the poor solvent is increased to increase the particle size of the polymer electrolyte aggregates. In No. 2, the solvent 3 was not added and no aggregate was formed. In each Example and Comparative Example, the type of the solvent 3 and its weight ratio in the dispersion solvent were as shown below.
Example 1 Solvent 3: Butyl acetate, 30%
Example 2 ... Solvent 3: Butyl acetate, 17%
Example 3 ... Solvent 3: Acetic acid, 13%
Example 4 ... Solvent 3: Tetrahydrofuran, 10%
Comparative Example 1 ... Solvent 3: Butyl acetate, 60%
Comparative Example 2 ... Solvent 3: None

〈高分子電解質の凝集体の平均粒子径測定〉
上記の触媒インクとは別に、上記重量比の混合溶媒と、高分子電解質溶液のみを混合し、粒度分布測定を行った。測定にはレーザー回折式粒度分布測定装置(SALD−2100、株式会社島津製作所製)を用いた。
<Measurement of average particle size of polymer electrolyte aggregate>
Apart from the catalyst ink, only the mixed solvent of the above weight ratio and the polymer electrolyte solution were mixed, and the particle size distribution was measured. For the measurement, a laser diffraction particle size distribution measuring device (SALD-2100, manufactured by Shimadzu Corporation) was used.

〈膜電極接合体の作製〉
PTFEシートを基材として、触媒インクを、ドクターブレードを用いて塗布し、80℃に設定したオーブン内で5分間乾燥させて転写フィルム上に電極触媒層を作製した。これを正方形に一組打ち抜き、高分子電解質膜(Nafion212:登録商標、Dupont社製)の両面にそれぞれ対面するように配置した積層体とし、130℃で10分間、ホットプレスを行った。ホットプレスを行った後、基材のPTFEを剥離することで、膜電極接合体を作製した。
<Preparation of membrane electrode assembly>
Using PTFE sheet as a base material, catalyst ink was applied using a doctor blade and dried in an oven set at 80 ° C. for 5 minutes to prepare an electrode catalyst layer on the transfer film. A set of this was punched out into a square shape, and a laminated body arranged so as to face both surfaces of a polymer electrolyte membrane (Nafion 212: registered trademark, manufactured by Dupont) was hot-pressed at 130 ° C. for 10 minutes. After hot pressing, the membrane electrode assembly was produced by peeling off the PTFE of the base material.

〈発電特性測定〉
実施例および比較例の各膜電極接合体にガス拡散層としてのカーボンクロスを挟持するように貼り合わせ、発電評価セル内に設置した。これを、燃料電池測定装置を用いてセル温度80℃で電流電圧測定を行った。加湿条件は、アノード、カソードともに25%RHとした。燃料ガスとして水素、酸化剤ガスとして空気を用いた。背圧は100kPaとした。
<Measurement of power generation characteristics>
The membrane electrode assemblies of Examples and Comparative Examples were bonded together so as to sandwich a carbon cloth as a gas diffusion layer, and installed in a power generation evaluation cell. This was measured at a cell temperature of 80 ° C. using a fuel cell measuring device. The humidification condition was 25% RH for both the anode and the cathode. Hydrogen was used as the fuel gas and air was used as the oxidant gas. The back pressure was 100 kPa.

(結果)
実施例1〜4、比較例1、2の各種分散溶媒の種類、分散溶媒と高分子電解質を混合した場合の平均粒子径、発電時の電圧を図2に示した。
(result)
The types of various dispersion solvents of Examples 1 to 4 and Comparative Examples 1 and 2, the average particle diameter when the dispersion solvent and the polymer electrolyte are mixed, and the voltage during power generation are shown in FIG.

図2を参照すると、実施例1〜4は、溶媒中での高分子電解質の平均粒子径が1μm以上5μm以下の範囲に収まっている。一方、比較例1では貧溶媒の割合が多いため凝集体が大きく、比較例2では良溶媒のアルコール及び水のみであるため、粒度は観測されなかった。   Referring to FIG. 2, in Examples 1 to 4, the average particle diameter of the polymer electrolyte in the solvent is in the range of 1 μm to 5 μm. On the other hand, in Comparative Example 1, since the proportion of the poor solvent is large, the aggregates are large. In Comparative Example 2, since only the good solvent alcohol and water are used, no particle size was observed.

発電特性評価の結果について図2を参照すると、0.2A/cm、および1.0A/cmの各電流密度点における、電圧値を各々比較したところ、良溶媒を用いた比較例2に対して、実施例1〜4は、各電流密度点において、数十mV高い電圧を示した。また、平均粒子径が大きかった比較例1は、高分子電解質が偏在してしまったため発電性能が低く、電流密度値まで発電することができなかった。 Referring to Figure 2 the results of the power generation characteristic evaluation, at each current density points of 0.2 A / cm 2, and 1.0A / cm 2, it was compared each voltage value, the comparative example 2 using the good solvent On the other hand, Examples 1-4 showed a voltage several tens mV higher at each current density point. In Comparative Example 1 in which the average particle size was large, the polymer electrolyte was unevenly distributed, so the power generation performance was low, and it was not possible to generate power up to the current density value.

以上より、本発明の膜電極接合体によれば、発電性能が均一である。したがって、本発明は高分子電解質膜を用いた燃料電池、特に定置型コジェネレーションシステムや電気自動車などに好適に用いることができる。   As described above, according to the membrane electrode assembly of the present invention, the power generation performance is uniform. Therefore, the present invention can be suitably used for a fuel cell using a polymer electrolyte membrane, particularly a stationary cogeneration system and an electric vehicle.

1 触媒担持カーボン
11 触媒物質
12 カーボン
21 高分子電解質の被膜
22 高分子電解質の凝集体
23 橋架け状の高分子電解質
DESCRIPTION OF SYMBOLS 1 Catalyst support carbon 11 Catalytic substance 12 Carbon 21 Polymer electrolyte coating 22 Aggregate of polymer electrolyte 23 Bridge-shaped polymer electrolyte

Claims (11)

触媒担持カーボンと、分散溶媒と、高分子電解質とを含有する触媒インクを用いて電極触媒層を形成する燃料電池用電極触媒層の製造方法であって、
前記分散溶媒中において前記高分子電解質は平均粒子径が1μm以上5μm以下の凝集体であることを特徴とする燃料電池用電極触媒層の製造方法。
A method for producing an electrode catalyst layer for a fuel cell, wherein an electrode catalyst layer is formed using a catalyst ink containing a catalyst-supporting carbon, a dispersion solvent, and a polymer electrolyte,
The method for producing an electrode catalyst layer for a fuel cell, wherein the polymer electrolyte is an aggregate having an average particle size of 1 μm or more and 5 μm or less in the dispersion solvent.
前記触媒担持カーボンの触媒の粒径は、0.5nm以上20nm以下であることを特徴とする請求項1に記載の燃料電池用電極触媒層の製造方法。   2. The method for producing an electrode catalyst layer for a fuel cell according to claim 1, wherein a particle size of the catalyst of the catalyst-supporting carbon is 0.5 nm or more and 20 nm or less. 前記触媒担持カーボンの、前記触媒を担持するためのカーボン粒子の粒径は、10nm以上1000nm以下であることを特徴とする請求項1または2に記載の燃料電池用電極触媒層の製造方法。   3. The method for producing an electrode catalyst layer for a fuel cell according to claim 1, wherein the catalyst-supporting carbon has a carbon particle size for supporting the catalyst of 10 nm to 1000 nm. 前記分散溶媒に占める溶媒の重量比は、5%以上55%以下であることを特徴とする請求項1乃至3のいずれかに記載の燃料電池用電極触媒層の製造方法。   The method for producing a fuel cell electrode catalyst layer according to any one of claims 1 to 3, wherein a weight ratio of the solvent in the dispersion solvent is 5% or more and 55% or less. 前記分散溶媒は、1種または2種以上からなる混合溶媒であることを特徴とする請求項1乃至4のいずれかに記載の燃料電池用電極触媒層の製造方法。   The method for producing an electrode catalyst layer for a fuel cell according to any one of claims 1 to 4, wherein the dispersion solvent is a mixed solvent composed of one kind or two or more kinds. 前記分散溶媒は、酢酸エチル、酢酸ブチル、酢酸イソブチル、酢酸、エチレングリコールモノメチルエーテル、またはエチレングリコールモノエチルエーテルから選択される1種または2種以上を含む混合溶媒であることを特徴とする請求項5に記載の燃料電池用電極触媒層の製造方法。   The dispersion solvent is a mixed solvent containing one or more selected from ethyl acetate, butyl acetate, isobutyl acetate, acetic acid, ethylene glycol monomethyl ether, or ethylene glycol monoethyl ether. 6. A method for producing an electrode catalyst layer for a fuel cell according to 5. 前記触媒担持カーボンと、前記分散溶媒と、前記高分子電解質とを混合し、分散処理を加える工程を含むことを特徴とする請求項1乃至6のいずれか1項に記載の燃料電池用電極触媒層の製造方法。   The electrode catalyst for a fuel cell according to any one of claims 1 to 6, further comprising a step of mixing the catalyst-supporting carbon, the dispersion solvent, and the polymer electrolyte and applying a dispersion treatment. Layer manufacturing method. 請求項1乃至7のいずれか1項に記載の製造方法で製造される電極触媒層を有することを特徴とする膜電極接合体。   A membrane / electrode assembly comprising an electrode catalyst layer produced by the production method according to claim 1. 触媒担持カーボンと、分散溶媒と、高分子電解質とを含有する触媒インクであって、
前記分散溶媒中において前記高分子電解質は平均粒子径が1μm以上5μm以下の凝集体であることを特徴とする触媒インク。
A catalyst ink containing a catalyst-supporting carbon, a dispersion solvent, and a polymer electrolyte,
The catalyst ink, wherein the polymer electrolyte is an aggregate having an average particle diameter of 1 μm or more and 5 μm or less in the dispersion solvent.
前記分散溶媒は、1種または2種以上からなる混合溶媒であることを特徴とする請求項9に記載の触媒インク。   The catalyst ink according to claim 9, wherein the dispersion solvent is a mixed solvent composed of one kind or two or more kinds. 前記分散溶媒は、酢酸エチル、酢酸ブチル、酢酸イソブチル、酢酸、エチレングリコールモノメチルエーテル、またはエチレングリコールモノエチルエーテルから選択される1種または2種以上を含む混合溶媒であることを特徴とする請求項10に記載の触媒インク。   The dispersion solvent is a mixed solvent containing one or more selected from ethyl acetate, butyl acetate, isobutyl acetate, acetic acid, ethylene glycol monomethyl ether, or ethylene glycol monoethyl ether. 10. The catalyst ink according to 10.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011070980A (en) * 2009-09-28 2011-04-07 Toppan Printing Co Ltd Polymer electrolyte of solid polymer fuel cell, method for manufacturing the same, membrane-electrode assembly containing polymer electrolyte, and method for manufacturing the same membrane-electrode assembly
JP2013030286A (en) * 2011-07-27 2013-02-07 Toyota Motor Corp Catalyst ink for fell cell
JP2013058436A (en) * 2011-09-09 2013-03-28 Tokyo Institute Of Technology Electrode catalyst for polymer electrolyte fuel cell and method for manufacturing the same
JP2016201314A (en) * 2015-04-13 2016-12-01 トヨタ自動車株式会社 Method of manufacturing electrode for fuel battery

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003282088A (en) * 2002-03-20 2003-10-03 Matsushita Electric Ind Co Ltd Polymerelectrolyte type fuel cell and production process thereof
JP2003297373A (en) * 2002-04-08 2003-10-17 Matsushita Electric Ind Co Ltd Coating for catalyst bed and manufacturing method of electrolyte membrane electrode junction body using it
JP2004158290A (en) * 2002-11-06 2004-06-03 Matsushita Electric Ind Co Ltd Polymer electrolyte fuel cell and method of manufacturing its electrode
JP2005100679A (en) * 2003-09-22 2005-04-14 Tomoegawa Paper Co Ltd Gas diffusion electrode, its manufacturing method, and solid polymer fuel cell using this
JP2005108551A (en) * 2003-09-29 2005-04-21 Tomoegawa Paper Co Ltd Catalyst film for solid polymer fuel cells, its manufacturing method and fuel cell using the same
JP2009218006A (en) * 2008-03-07 2009-09-24 Nissan Motor Co Ltd Method of manufacturing electrolyte membrane-electrode assembly

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003282088A (en) * 2002-03-20 2003-10-03 Matsushita Electric Ind Co Ltd Polymerelectrolyte type fuel cell and production process thereof
JP2003297373A (en) * 2002-04-08 2003-10-17 Matsushita Electric Ind Co Ltd Coating for catalyst bed and manufacturing method of electrolyte membrane electrode junction body using it
JP2004158290A (en) * 2002-11-06 2004-06-03 Matsushita Electric Ind Co Ltd Polymer electrolyte fuel cell and method of manufacturing its electrode
JP2005100679A (en) * 2003-09-22 2005-04-14 Tomoegawa Paper Co Ltd Gas diffusion electrode, its manufacturing method, and solid polymer fuel cell using this
JP2005108551A (en) * 2003-09-29 2005-04-21 Tomoegawa Paper Co Ltd Catalyst film for solid polymer fuel cells, its manufacturing method and fuel cell using the same
JP2009218006A (en) * 2008-03-07 2009-09-24 Nissan Motor Co Ltd Method of manufacturing electrolyte membrane-electrode assembly

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011070980A (en) * 2009-09-28 2011-04-07 Toppan Printing Co Ltd Polymer electrolyte of solid polymer fuel cell, method for manufacturing the same, membrane-electrode assembly containing polymer electrolyte, and method for manufacturing the same membrane-electrode assembly
JP2013030286A (en) * 2011-07-27 2013-02-07 Toyota Motor Corp Catalyst ink for fell cell
JP2013058436A (en) * 2011-09-09 2013-03-28 Tokyo Institute Of Technology Electrode catalyst for polymer electrolyte fuel cell and method for manufacturing the same
JP2016201314A (en) * 2015-04-13 2016-12-01 トヨタ自動車株式会社 Method of manufacturing electrode for fuel battery

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