JP2005259513A - Electrode for fuel cell, membrane/electrode connected object for fuel cell, and solid polymer fuel cell - Google Patents

Electrode for fuel cell, membrane/electrode connected object for fuel cell, and solid polymer fuel cell Download PDF

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JP2005259513A
JP2005259513A JP2004069240A JP2004069240A JP2005259513A JP 2005259513 A JP2005259513 A JP 2005259513A JP 2004069240 A JP2004069240 A JP 2004069240A JP 2004069240 A JP2004069240 A JP 2004069240A JP 2005259513 A JP2005259513 A JP 2005259513A
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electrode
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proton conductive
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Mitsuyasu Kawahara
光泰 川原
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Toyota Motor Corp
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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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Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode and a membrane/electrode connected object for a fuel cell, which enable the fuel cell to have excellent battery property by realizing their high drainage natures maintaining their water retention natures to improve their gas diffusion natures. <P>SOLUTION: The electrode for the fuel cell has a catalyst layer containing dispersed catalyst grains and proton conduction electrolyte nano particles, and the membrane/electrode connected object consists of at least a fuel-electrode, a proton conduction electrolyte membrane, and an air-electrode. At least one of the fuel-electrode and the air-electrode has a catalyst layer containing the dispersed catalyst grains and the proton conduction electrolyte nano particles. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、燃料電池用電極、膜/電極接合体及びこれを備える固体高分子型燃料電池に関する。   The present invention relates to a fuel cell electrode, a membrane / electrode assembly, and a polymer electrolyte fuel cell including the same.

燃料電池は、電解質膜の両面に接合した一対の電極を有し、それぞれの電極に対して、水素を含有する又は水素を発生する燃料ガス、酸素を含有する酸化剤ガスを供給し、電気化学反応による電気エネルギーを得るものである。プロトン伝導性電解質膜を用いた固体高分子型燃料電池の場合には、燃料電池の燃料極及び空気極の触媒層では、下記に示す電気化学反応が進行している。   A fuel cell has a pair of electrodes joined to both surfaces of an electrolyte membrane, and supplies a fuel gas containing hydrogen or generating hydrogen, an oxidant gas containing oxygen to each electrode, and electrochemical Electric energy is obtained by reaction. In the case of a polymer electrolyte fuel cell using a proton conductive electrolyte membrane, the following electrochemical reaction proceeds in the fuel electrode and air electrode catalyst layers of the fuel cell.

Figure 2005259513
Figure 2005259513

すなわち、燃料極において、燃料ガスから供給された水素の酸化反応によりプロトン(H)と電子が生じ、プロトンは電解質膜を通って、一方、電子は外部回路を通って空気極へと移動する。そして、空気極において、酸化剤ガスから供給された酸素と燃料極から移動してきたプロトン及び電子が反応して水が生成する。 That is, at the fuel electrode, protons (H + ) and electrons are generated by the oxidation reaction of hydrogen supplied from the fuel gas, and the protons pass through the electrolyte membrane, while the electrons move through the external circuit to the air electrode. . In the air electrode, the oxygen supplied from the oxidant gas reacts with the protons and electrons moving from the fuel electrode to produce water.

高い電池特性を有する燃料電池とするためには、上記電気化学反応を円滑に効率良く進行させることが必要であり、そのためには燃料極側から電解質膜を通り、空気極側に至るまでプロトン伝導性を高くすることが重要となる。燃料極で発生したプロトン(H)は、空気極側へ水を同伴して移動するので、燃料極、電解質膜及び空気極を高い湿潤状態に保ち、プロトン伝導性を確保することが肝要である。 In order to obtain a fuel cell having high battery characteristics, it is necessary to allow the above-described electrochemical reaction to proceed smoothly and efficiently. For this purpose, proton conduction from the fuel electrode side through the electrolyte membrane to the air electrode side is required. It is important to increase the nature. Protons (H + ) generated at the fuel electrode move with water to the air electrode side, so it is important to keep the fuel electrode, electrolyte membrane, and air electrode in a highly moist state to ensure proton conductivity. is there.

また、燃料極及び空気極の触媒層が乾燥すると、その乾燥部分の触媒は電気化学反応に寄与しなくなるので、発電効率の低下を招く。さらに、触媒層の乾燥に伴って、電解質膜も乾燥状態になりやすく、高い電池特性を得るためには、各電極の触媒層の乾燥を防ぐことが重要である。   Further, when the catalyst layer of the fuel electrode and the air electrode is dried, the catalyst in the dried portion does not contribute to the electrochemical reaction, which causes a decrease in power generation efficiency. Furthermore, as the catalyst layer is dried, the electrolyte membrane is also easily dried, and in order to obtain high battery characteristics, it is important to prevent the catalyst layer of each electrode from being dried.

触媒層は、従来、少なくともプロトン伝導性を有する樹脂を溶解させた電解質溶液と触媒とを混合、分散して得られる電極インクを用いて形成されており、このような溶液状の電解質を用いて形成された触媒層では、触媒粒間隙に電解質が含浸した状態でプロトン伝導路が形成されている。そのため、プロトン伝導性を上げるためにプロトン伝導性樹脂の量を増やすと、多孔質構造が形成され難くなることによって、ガス拡散性が低下したり、電気化学反応の場となる三相界面が十分確保できなくなったり、また、排水性が悪くなってフラッディングが起きやすくなる。中でも、上記電気化学反応による水の生成量が多い高電流域や、電気化学反応により生成する水に加えて、燃料極からプロトンに同伴して水が移動してくる空気極側の触媒層は、フラッディングが特に発生しやすい。   The catalyst layer is conventionally formed using electrode ink obtained by mixing and dispersing an electrolyte solution in which at least proton conductive resin is dissolved and a catalyst, and using such a solution electrolyte. In the formed catalyst layer, the proton conduction path is formed with the electrolyte impregnated in the catalyst particle gap. Therefore, if the amount of proton conductive resin is increased in order to increase proton conductivity, it becomes difficult to form a porous structure, resulting in a decrease in gas diffusibility and a sufficient three-phase interface serving as an electrochemical reaction field. It becomes impossible to secure, and drainage becomes worse and flooding is likely to occur. Above all, in addition to the high current region where the amount of water generated by the electrochemical reaction is large and the water generated by the electrochemical reaction, the catalyst layer on the air electrode side where water moves with protons from the fuel electrode Flooding is particularly likely to occur.

十分なプロトン伝導性と共に十分なガス拡散性を確保するため、表面が第一の電解質によって被覆された複数の触媒粒と、第二の電解質が凝集することによって形成された複数の電解質群とを備え、前記複数の触媒粒を前記複数の電解質群によって互いに連結してなる燃料電池用電極が特許文献1に記載されている。特許文献1によれば、この燃料電池用電極は、電解質群を備えることによりプロトン伝導性を確保し、これにより触媒粒に被覆させる電解質層の厚みを薄くすることでガス拡散性を確保するとしている。しかしながら、触媒層内の多孔質構造は形成され難く、また、多孔質構造を制御することは必ずしも容易でない。   In order to ensure sufficient gas conductivity as well as sufficient proton conductivity, a plurality of catalyst particles whose surfaces are coated with the first electrolyte and a plurality of electrolyte groups formed by aggregation of the second electrolyte Patent Document 1 discloses a fuel cell electrode comprising a plurality of catalyst particles connected to each other by a plurality of electrolyte groups. According to Patent Document 1, the fuel cell electrode is provided with an electrolyte group to ensure proton conductivity, thereby reducing the thickness of the electrolyte layer coated on the catalyst particles, thereby ensuring gas diffusibility. Yes. However, it is difficult to form a porous structure in the catalyst layer, and it is not always easy to control the porous structure.

また、固体高分子型燃料電池は、長期的な連続運転によるプロトン伝導性電解質膜及び触媒層に含まれるプロトン伝導性電解質の劣化が懸念されており、長期間にわたる運転後も安定した発電特性を有するプロトン伝導性電解質の開発が望まれている。   In addition, solid polymer fuel cells are concerned about the deterioration of the proton conductive electrolyte contained in the proton conductive electrolyte membrane and the catalyst layer due to long-term continuous operation, and have stable power generation characteristics even after long-term operation. Development of a proton-conducting electrolyte is desired.

特開平11−126615号公報Japanese Patent Laid-Open No. 11-126615

本発明は、保水性を保持しつつ高い排水性を有し、ガス拡散性を向上させることにより、優れた電池特性を有する燃料電池用電極及び膜/電極接合体を提供することを目的とする。   It is an object of the present invention to provide a fuel cell electrode and a membrane / electrode assembly having excellent battery characteristics by having high drainage while maintaining water retention and improving gas diffusibility. .

本発明により提供される燃料電池用電極は、触媒粒と、プロトン伝導性電解質ナノ粒子とを分散させてなる触媒層を有することを特徴とするものである。   The fuel cell electrode provided by the present invention is characterized by having a catalyst layer in which catalyst particles and proton conductive electrolyte nanoparticles are dispersed.

また、本発明により提供される膜/電極接合体は、少なくとも燃料極、プロトン伝導性電解質膜、及び空気極から構成される膜/電極接合体であって、燃料極及び空気極の少なくとも一方が、触媒粒と、プロトン伝導性電解質ナノ粒子とを分散させてなる触媒層を有することを特徴とするものである。電解質としてプロトン伝導性電解質ナノ粒子を用い、触媒粒とともに触媒層中に分散させることにより、高い保水性と排水性を兼ね備え、ガス拡散性及び触媒利用率に優れた触媒層が得られる。上記プロトン伝導性電解質ナノ粒子がプロトン伝導性耐熱性樹脂を含有する場合、プロトン伝導性電解質ナノ粒子の耐熱性を向上させることができる。プロトン伝導性耐熱性樹脂としては、プロトン伝導性官能基を導入したエンジニアリングプラスチックが好ましい。また、プロトン伝導性電解質ナノ粒子としては、平均粒径が50〜300nmであることが好ましい。   The membrane / electrode assembly provided by the present invention is a membrane / electrode assembly including at least a fuel electrode, a proton conductive electrolyte membrane, and an air electrode, and at least one of the fuel electrode and the air electrode is And a catalyst layer in which catalyst particles and proton conductive electrolyte nanoparticles are dispersed. By using proton conductive electrolyte nanoparticles as the electrolyte and dispersing them in the catalyst layer together with the catalyst particles, a catalyst layer having both high water retention and drainage properties and excellent gas diffusibility and catalyst utilization can be obtained. When the proton conductive electrolyte nanoparticles contain a proton conductive heat-resistant resin, the heat resistance of the proton conductive electrolyte nanoparticles can be improved. As the proton conductive heat-resistant resin, an engineering plastic into which a proton conductive functional group is introduced is preferable. In addition, the proton conductive electrolyte nanoparticles preferably have an average particle size of 50 to 300 nm.

本発明に係る膜/電極接合体は、固体高分子型燃料電池に好適に利用することができ、高い発電特性を有する固体高分子型燃料電池を提供することができる。   The membrane / electrode assembly according to the present invention can be suitably used for a polymer electrolyte fuel cell, and can provide a polymer electrolyte fuel cell having high power generation characteristics.

本発明に係る燃料電池用電極及び膜/電極接合体は、触媒層内にプロトン伝導路を形成する電解質成分としてプロトン伝導性電解質ナノ粒子を用い、触媒粒とともに触媒層中に分散させることで、触媒層内に多孔質構造を形成させ、保水性を維持しつつも高い排水性を付与することにより、触媒層の乾燥及びフラッディングを防止することができる。その結果、本発明の燃料電池用電極及び膜/電極接合体は、ガス拡散性及び触媒利用率が向上し、発電性能の低下を阻止した優れた電池特性を有する。さらに、上記ナノ粒子の粒径及び量は制御することが可能であり、これらを制御することで多孔質構造中の隙間を調節することができるため、排水性、触媒の有効面積及びガス拡散経路等の触媒層の諸特性を最適化することができる。しかも、触媒利用率を向上させることにより、触媒使用量の削減も可能である。   The fuel cell electrode and membrane / electrode assembly according to the present invention use proton conductive electrolyte nanoparticles as an electrolyte component that forms a proton conduction path in the catalyst layer, and is dispersed in the catalyst layer together with the catalyst particles. By forming a porous structure in the catalyst layer and providing high drainage while maintaining water retention, drying and flooding of the catalyst layer can be prevented. As a result, the fuel cell electrode and membrane / electrode assembly of the present invention have excellent battery characteristics in which gas diffusibility and catalyst utilization are improved, and deterioration in power generation performance is prevented. Furthermore, the particle size and amount of the nanoparticles can be controlled, and by controlling these, the gaps in the porous structure can be adjusted, so drainage, effective catalyst area and gas diffusion path Thus, various characteristics of the catalyst layer can be optimized. In addition, the amount of catalyst used can be reduced by improving the catalyst utilization rate.

また、プロトン伝導性電解質ナノ粒子中に含まれるプロトン伝導性樹脂として、プロトン伝導性耐熱性樹脂を用いることによって、高温域での作動環境における長期連続運転後も安定した発電性能を発揮することが可能である。特に、プロトン伝導性耐熱性樹脂として、プロトン伝導性官能基を導入したエンジニアリングプラスチックを用いた場合、プロトン伝導性電解質ナノ粒子の化学的安定性及び物理的安定性が高くなり、燃料電池の作動耐久性を向上させることができる。   In addition, by using a proton conductive heat-resistant resin as the proton conductive resin contained in the proton conductive electrolyte nanoparticles, stable power generation performance can be exhibited even after long-term continuous operation in a high temperature operating environment. Is possible. In particular, when engineering plastics with proton-conductive functional groups are used as proton-conductive heat-resistant resins, the chemical and physical stability of proton-conductive electrolyte nanoparticles is increased, and the operation durability of fuel cells is increased. Can be improved.

まず、固体高分子型燃料電池の構成の概略を図1に模式的に示す。図1において、プロトン伝導性電解質膜1の片面に燃料極触媒層2、もう一面に空気極触媒層3が設けられている。燃料極6は、少なくとも触媒層2を備えるものであり、さらに触媒層2の外面に、ガス拡散層4を備える多層構造を有していてもよい。空気極7も同様に、少なくとも触媒層3を備えるものであり、さらに触媒層3の外面にガス拡散層5を備える多層構造を有していてもよい。通常、燃料極6、電解質膜1、空気極7から構成される膜/電極接合体の各電極に反応ガス(燃料ガス又は酸化剤ガス)を供給し、且つ電気化学反応により生成する水分や余剰のガスを排出するため、各電極の外側にはガス流路8、9を画成するセパレータ10、11が設けられている。   First, an outline of the configuration of a solid polymer fuel cell is schematically shown in FIG. In FIG. 1, a fuel electrode catalyst layer 2 is provided on one side of a proton conductive electrolyte membrane 1, and an air electrode catalyst layer 3 is provided on the other side. The fuel electrode 6 includes at least the catalyst layer 2 and may have a multilayer structure including the gas diffusion layer 4 on the outer surface of the catalyst layer 2. Similarly, the air electrode 7 includes at least the catalyst layer 3, and may further have a multilayer structure including the gas diffusion layer 5 on the outer surface of the catalyst layer 3. Usually, a reactive gas (fuel gas or oxidant gas) is supplied to each electrode of a membrane / electrode assembly composed of the fuel electrode 6, the electrolyte membrane 1, and the air electrode 7, and moisture or surplus generated by an electrochemical reaction In order to discharge the gas, separators 10 and 11 defining gas flow paths 8 and 9 are provided outside each electrode.

本発明の燃料電池用電極は、触媒粒と、プロトン伝導性電解質ナノ粒子とを分散させてなる触媒層を有することを特徴とする。また、本発明の膜/電極接合体は、少なくとも燃料極、プロトン伝導性電解質膜、及び空気極から構成される膜/電極接合体であって、燃料極及び空気極の少なくとも一方が、触媒粒と、プロトン伝導性電解質ナノ粒子とを分散させてなる触媒層を有することを特徴とする。図2は、本発明に係る燃料電池用電極及び膜/電極接合体の触媒層の構造の概略を示す模式図、図3は、プロトン伝導性を有する樹脂を溶解させた電解質溶液を用いて作製された従来例の触媒層の構造の概略を示す模式図である。なお、図2及び図3は、触媒粒として触媒活性成分を表面に担持した導電性材料粒子を用いた場合の模式図である。   The electrode for a fuel cell of the present invention is characterized by having a catalyst layer in which catalyst particles and proton conductive electrolyte nanoparticles are dispersed. The membrane / electrode assembly of the present invention is a membrane / electrode assembly composed of at least a fuel electrode, a proton conductive electrolyte membrane, and an air electrode, and at least one of the fuel electrode and the air electrode has catalyst particles. And a catalyst layer in which proton conductive electrolyte nanoparticles are dispersed. FIG. 2 is a schematic diagram showing an outline of the structure of the catalyst layer of the fuel cell electrode and the membrane / electrode assembly according to the present invention, and FIG. 3 is prepared using an electrolyte solution in which a proton-conductive resin is dissolved. It is a schematic diagram which shows the outline of the structure of the catalyst layer of the conventional example made. 2 and 3 are schematic diagrams in the case of using conductive material particles carrying a catalytically active component on the surface as catalyst particles.

本発明の膜/電極接合体における触媒層は、電解質成分としてプロトン伝導性電解質ナノ粒子を用い、触媒粒と該プロトン伝導性電解質ナノ粒子を分散させてなるものである。図2に示すように、本発明の触媒層では、凝集した触媒粒の間隙にプロトン伝導性電解質ナノ粒子が粒子状態で存在しており、触媒粒とプロトン伝導性電解質ナノ粒子が混在して多孔質構造を形成している。ここで、ナノ粒子とは平均粒径が1μm未満の粒子であればよく、本発明において通常は、平均粒径が50〜300nmの範囲のものが用いられる。なお、プロトン伝導性電解質ナノ粒子の平均粒径は、SEM(走査電子顕微鏡)法、TEM(透過電子顕微鏡)法により測定することができる。   The catalyst layer in the membrane / electrode assembly of the present invention comprises proton conductive electrolyte nanoparticles as an electrolyte component, and catalyst particles and the proton conductive electrolyte nanoparticles are dispersed. As shown in FIG. 2, in the catalyst layer of the present invention, proton conductive electrolyte nanoparticles are present in the state of particles in the gaps between the aggregated catalyst particles, and the catalyst particles and proton conductive electrolyte nanoparticles are mixed and porous. A quality structure is formed. Here, the nanoparticles may be particles having an average particle diameter of less than 1 μm, and those having an average particle diameter in the range of 50 to 300 nm are usually used in the present invention. The average particle diameter of the proton conductive electrolyte nanoparticles can be measured by SEM (scanning electron microscope) method or TEM (transmission electron microscope) method.

従来の触媒層は、粒子化していないプロトン伝導性樹脂を溶解した電解質溶液を用いて形成していたため、触媒層内において触媒粒間隙のイオン伝導路は、図3に示すように、凝集させた触媒粒の表面に電解質皮膜又は空隙を埋める含浸相となって形成されていた。この状態では、触媒粒間隙を自由にコントロールできないため、触媒層内に多孔質構造を形成することが難しく、排水性や、空気極側の触媒層にあっては電気化学反応の場となる三相界面を改善することが困難であった。   Since the conventional catalyst layer is formed by using an electrolyte solution in which proton conductive resin that has not been granulated is dissolved, the ion conduction paths in the catalyst particle gaps in the catalyst layer are aggregated as shown in FIG. It was formed as an impregnation phase for filling the electrolyte film or voids on the surface of the catalyst particles. In this state, the catalyst particle gap cannot be freely controlled, so it is difficult to form a porous structure in the catalyst layer, and it is difficult to form a porous structure in the catalyst layer. It was difficult to improve the phase interface.

これに対し、本発明では、電解質として、プロトン伝導性電解質ナノ粒子を分散させた多孔質構造を有する触媒層とすることで、余剰の水分の排出性が向上し、フラッディングを防止することができる。さらには反応ガスの拡散性も向上するので、触媒の利用率も高めることができる。一方、多孔質構造とすることにより、毛細管現象による保水性が得られ、触媒層の湿潤状態は良好に保たれるため、プロトン伝導性の高い触媒層となる。特に、電気化学反応の場となる空気極側においては、反応ガスの拡散性、プロトン伝導性及び触媒の利用面積率の向上により三相界面が形成されやすくなるため、電極反応が十分に進行する。しかも、プロトン伝導性電解質ナノ粒子の量や粒径を調節することにより、多孔質構造の間隙を自由にコントロールすることで、上述したような触媒層の諸特性を最適化することができる。また、多孔質構造とすることにより、従来の皮膜化された又は含浸相としたプロトン伝導路を形成する場合と比べて、電解質の使用量も低減することができる。   On the other hand, in the present invention, as the electrolyte, a catalyst layer having a porous structure in which proton conductive electrolyte nanoparticles are dispersed can improve the discharge of excess water and prevent flooding. . Furthermore, since the diffusibility of the reaction gas is improved, the utilization factor of the catalyst can be increased. On the other hand, with a porous structure, water retention by capillary action is obtained, and the wet state of the catalyst layer is kept good, so that the catalyst layer has high proton conductivity. In particular, on the air electrode side where the electrochemical reaction takes place, a three-phase interface is easily formed by improving the diffusibility of the reaction gas, proton conductivity, and the utilization area ratio of the catalyst, and thus the electrode reaction proceeds sufficiently. . In addition, the characteristics of the catalyst layer as described above can be optimized by freely controlling the gap of the porous structure by adjusting the amount and particle size of the proton conductive electrolyte nanoparticles. Moreover, by using a porous structure, the amount of electrolyte used can also be reduced as compared with the case where a proton conduction path formed into a conventional film or impregnated phase is formed.

本発明において用いるプロトン伝導性電解質ナノ粒子は、電解質として、プロトン伝導性樹脂を主成分とするが、プロトン伝導性樹脂以外の電解質成分又はその他の成分を必要に応じて含有していてもよい。プロトン伝導性電解質ナノ粒子としては、プロトン伝導性電解質として用いられるプロトン伝導性を有する樹脂をナノ粒子化したものを用いることができる。具体的には、例えば、パーフルオロスルホン酸樹脂;イオン交換膜に用いられる炭化水素系樹脂等のプロトン伝導性樹脂をナノ粒子化することによって合成される。   The proton conductive electrolyte nanoparticles used in the present invention have a proton conductive resin as a main component as an electrolyte, but may contain an electrolyte component other than the proton conductive resin or other components as necessary. As the proton conductive electrolyte nanoparticles, those obtained by converting the proton conductive resin used as the proton conductive electrolyte into nanoparticles can be used. Specifically, for example, it is synthesized by forming nanoparticles of a proton conductive resin such as a perfluorosulfonic acid resin; a hydrocarbon resin used for an ion exchange membrane.

長期的な連続運転、中でも高温の作動環境における長期的な連続運転においては、これらの通常用いられているようなプロトン伝導性電解質樹脂では、微細なナノ粒子の状態で触媒層に分散させると、耐熱性が不十分であるため劣化し、安定した発電特性を示さない場合がある。この問題を回避するため、プロトン伝導性電解質ナノ粒子はプロトン伝導性耐熱性樹脂を含有することが好ましい。ここで、耐熱性とは、電解質樹脂中の強酸基が脱離する温度が高い性質を意味する。本発明における耐熱性としては、上記温度が200℃以上であることが望ましい。   In long-term continuous operation, particularly in long-term continuous operation in a high temperature operating environment, these normally used proton conductive electrolyte resins, when dispersed in the catalyst layer in the form of fine nanoparticles, It may deteriorate due to insufficient heat resistance and may not show stable power generation characteristics. In order to avoid this problem, the proton conductive electrolyte nanoparticles preferably contain a proton conductive heat-resistant resin. Here, the heat resistance means a property having a high temperature at which a strong acid group in the electrolyte resin is eliminated. As the heat resistance in the present invention, the above temperature is desirably 200 ° C. or higher.

プロトン伝導性耐熱性樹脂としては、例えば、プロトン伝導性を有する官能基を導入したエンジニアリングプラスチックが挙げられる。具体的には、ポリエーテルエーテルケトン、ポリエーテルイミド、ポリアミドイミド、ポリイミド、ポリエーテルスルホン、ポリスルホン等のエンジニアリングプラスチックにスルホン酸基、カルボン酸基及びリン酸基等のプロトン伝導性官能基を導入したもの等が挙げられる。中でも、高いプロトン伝導性及び耐熱性を有するスルホン化したポリイミドが好ましい。プロトン伝導性官能基を導入したエンジニアリングプラスチックは、化学的安定性及び物理的安定性が高いため、これらのエンジニアリングプラスチックをプロトン伝導性電解質ナノ粒子中に含有させることによって、長期連続運転後も安定した発電性能を示す作動耐久性に優れた触媒層を得ることができる。特に、高温域での作動環境においても、触媒層中の電解質は劣化し難く、安定した連続発電が可能である。   Examples of the proton conductive heat-resistant resin include engineering plastics into which a functional group having proton conductivity is introduced. Specifically, proton conductive functional groups such as sulfonic acid groups, carboxylic acid groups and phosphoric acid groups were introduced into engineering plastics such as polyetheretherketone, polyetherimide, polyamideimide, polyimide, polyethersulfone, and polysulfone. And the like. Among them, a sulfonated polyimide having high proton conductivity and heat resistance is preferable. Engineering plastics with proton-conducting functional groups introduced have high chemical and physical stability. By including these engineering plastics in proton-conducting electrolyte nanoparticles, they are stable even after long-term continuous operation. A catalyst layer exhibiting power generation performance and excellent operating durability can be obtained. In particular, even in an operating environment in a high temperature range, the electrolyte in the catalyst layer is hardly deteriorated, and stable continuous power generation is possible.

プロトン伝導性樹脂は、1種のみ又は2種以上を組み合わせて用いることができる。また、プロトン伝導性樹脂とマトリックスポリマーを高分子間相互作用により複合化することによって、複合型プロトン伝導性電解質ナノ粒子とすることも可能である。   Proton conductive resins can be used alone or in combination of two or more. In addition, it is possible to form composite proton conductive electrolyte nanoparticles by combining a proton conductive resin and a matrix polymer by the interaction between polymers.

プロトン伝導性電解質ナノ粒子は、プロトン伝導性樹脂の重合方法を選択し、反応溶媒と樹脂との親和性や樹脂の分子量を調節することによって、その粒径をナノオーダーで制御できる。プロトン伝導性電解質ナノ粒子の粒径を制御することで、触媒層の多孔質構造を自由に調節することが可能であり、すなわち、温度、湿度等燃料電池の作動条件に応じて、触媒の利用面積、反応ガスの拡散経路、排水性、保水性等の触媒層の様々な特性を最適化することができる。   The proton conductive electrolyte nanoparticles can be controlled in nano order by selecting the polymerization method of the proton conductive resin and adjusting the affinity between the reaction solvent and the resin and the molecular weight of the resin. By controlling the particle size of the proton conductive electrolyte nanoparticles, it is possible to freely adjust the porous structure of the catalyst layer, that is, use of the catalyst according to the operating conditions of the fuel cell such as temperature and humidity. Various characteristics of the catalyst layer such as area, reaction gas diffusion path, drainage, and water retention can be optimized.

次に、以上のようなプロトン伝導性電解質ナノ粒子を用いた触媒層を有する本発明の膜/電極接合体の形成方法について説明する。
まず、上述したようなプロトン伝導性電解質ナノ粒子を、ジメチルホルムアミド、N−メチルピロリドン、N,N’−ジメチルアセトアミド、ジメチルスルホキシド等の極性溶媒に分散させた分散溶液を調製する。この分散溶液中のプロトン伝導性電解質ナノ粒子の含有量は1〜10重量%程度とし、極性溶媒の含有量は90〜99重量%程度とすればよい。
Next, a method for forming a membrane / electrode assembly of the present invention having a catalyst layer using the proton conductive electrolyte nanoparticles as described above will be described.
First, a dispersion solution in which the proton conductive electrolyte nanoparticles as described above are dispersed in a polar solvent such as dimethylformamide, N-methylpyrrolidone, N, N′-dimethylacetamide, dimethylsulfoxide, etc. is prepared. The content of proton conductive electrolyte nanoparticles in the dispersion solution may be about 1 to 10% by weight, and the content of the polar solvent may be about 90 to 99% by weight.

得られたナノ粒子分散溶液は、触媒粒と混練して、プロトン伝導性電解質ナノ粒子と触媒粒とが分散された電極インクとする。本発明において用いることができる触媒粒としては、燃料極における水素の酸化反応、空気極における酸素の還元反応に対して触媒作用を有するものであれば特に限定されず、各電極でそれぞれ適したものを選ぶことができる。例えば、白金又は、ルテニウム、鉄、マンガン等その他の金属と白金からなる合金等の粒子等の触媒活性成分を表面に担持させた粒や触媒活性成分そのものからなる粒が挙げられる。本発明においては、カーボンブラック、炭素繊維のような炭素材料等の導電性材料に触媒活性成分を担持させたものを使用することが好ましい。中でも、カーボン粒子のような炭素材料からなる粒子に白金微粒子を担持させた形態のものが好ましい。排水性やガス拡散性の向上等の本発明による効果を十分得るためには、触媒層中に形成する多孔質構造を制御することが重要であることから、カーボン粒子のような導電性材料は0.01〜1μm程度の平均粒径を有していることが好ましい。同様の観点から、導電性材料に担持させる触媒活性成分は、1〜6nm程度の平均粒径を有していることが好ましい。これら導電性材料及び触媒活性成分の平均粒径は、SEM法、TEM法により測定することができる。触媒粒として触媒活性成分を導電性材料に担持させたものを用いる場合には、触媒粒全体に対して10〜60重量%程度の触媒活性成分を担持させたものが使用できる。本発明によれば、触媒利用率を向上させることができるため、触媒の使用量の削減を図ることが可能であり、コストの削減も達成される。   The obtained nanoparticle dispersion solution is kneaded with catalyst particles to obtain an electrode ink in which proton conductive electrolyte nanoparticles and catalyst particles are dispersed. The catalyst particles that can be used in the present invention are not particularly limited as long as they have a catalytic action for the hydrogen oxidation reaction at the fuel electrode and the oxygen reduction reaction at the air electrode, and are suitable for each electrode. Can be selected. For example, particles having catalytic active components such as platinum or particles of an alloy made of platinum and other metals such as ruthenium, iron, and manganese, and particles made of the catalytic active components themselves may be used. In the present invention, it is preferable to use a material in which a catalytically active component is supported on a conductive material such as carbon black or carbon fiber. Among these, a form in which platinum particles are supported on particles made of a carbon material such as carbon particles is preferable. In order to sufficiently obtain the effects of the present invention such as improved drainage and gas diffusivity, it is important to control the porous structure formed in the catalyst layer. It is preferable to have an average particle diameter of about 0.01 to 1 μm. From the same viewpoint, the catalytically active component supported on the conductive material preferably has an average particle diameter of about 1 to 6 nm. The average particle diameter of these conductive materials and catalytically active components can be measured by SEM method and TEM method. In the case of using the catalyst particles in which the catalytic active component is supported on the conductive material, the catalyst particles having about 10 to 60% by weight of the catalytic active component supported on the entire catalyst particles can be used. According to the present invention, since the catalyst utilization rate can be improved, it is possible to reduce the amount of catalyst used, and cost reduction is also achieved.

電極インクは、プロトン伝導性電解質ナノ粒子、極性溶媒、触媒粒、及び必要に応じて撥水性材料や結着剤等その他成分を、通常の方法により混合・分散させることにより得られる。電極インク中の各成分の濃度は、特に限定されるものではなく、通常、プロトン伝導性電解質ナノ粒子を1〜10重量%程度、極性溶媒を70〜89重量%程度、触媒粒を10〜20重量%程度とすればよい。   The electrode ink is obtained by mixing and dispersing proton conductive electrolyte nanoparticles, polar solvent, catalyst particles, and other components such as a water-repellent material and a binder as required, by a usual method. The concentration of each component in the electrode ink is not particularly limited. Usually, the proton conductive electrolyte nanoparticles are about 1 to 10% by weight, the polar solvent is about 70 to 89% by weight, and the catalyst particles are 10 to 20%. What is necessary is just about weight%.

このようにして得られた電極インクを、カーボンペーパーやカーボンクロス等の電気伝導性多孔質織布又は不織布の表面をポリテトラフルオロエチレン等によってコーティングすることで撥水化したガス拡散層上に直接塗布・乾燥することによって、電極が形成される。電極インクの塗布方法は、特に限定されず、例えば、スプレー法、スクリーン印刷法等の種々の方法から適宜選択することができる。本発明においては、上記のようにガス拡散層上に直接塗布・乾燥することによって形成する方法に限らず、例えば、電極インクをポリテトラフルオロエチレン等の基材上に塗布・乾燥したものをガス拡散層と接合させ、基材を剥がすことによって形成することもできる。また、本発明により得られる触媒層は、ガス拡散性に優れるため、ガス拡散層を設けずに電極を形成することもできる。
得られた触媒層は、プロトン伝導性電解質ナノ粒子を10〜50重量%程度、触媒活性成分を50〜90重量%程度含有していることが好ましい。
The electrode ink thus obtained is directly applied on the gas diffusion layer made water repellent by coating the surface of an electrically conductive porous woven fabric or nonwoven fabric such as carbon paper or carbon cloth with polytetrafluoroethylene or the like. An electrode is formed by applying and drying. The method for applying the electrode ink is not particularly limited, and can be appropriately selected from various methods such as a spray method and a screen printing method. In the present invention, the method is not limited to the method of forming by directly applying and drying on the gas diffusion layer as described above. For example, a gas obtained by applying and drying electrode ink on a substrate such as polytetrafluoroethylene is used as a gas. It can also be formed by bonding to a diffusion layer and peeling off the substrate. Moreover, since the catalyst layer obtained by this invention is excellent in gas diffusivity, it can also form an electrode, without providing a gas diffusion layer.
The obtained catalyst layer preferably contains about 10 to 50% by weight of proton conductive electrolyte nanoparticles and about 50 to 90% by weight of catalytically active components.

次に、本発明の膜/電極接合体の製造方法について説明する。上記のようにして得られた燃料極及び空気極を、触媒層がガス拡散層よりも内側になるようにして電解質膜を挟み、ホットプレスやロールプレス等により圧着することで、膜/電極接合体が得られる。例えば、ホットプレスにて圧着する場合には、50〜200℃、0.1〜10MPa程度の条件で圧着できる。   Next, the manufacturing method of the membrane / electrode assembly of the present invention will be described. The fuel electrode and the air electrode obtained as described above are sandwiched between the electrolyte membrane so that the catalyst layer is on the inner side of the gas diffusion layer, and are pressure-bonded by hot press, roll press, etc. The body is obtained. For example, when pressure bonding is performed by a hot press, the pressure bonding can be performed under conditions of about 50 to 200 ° C. and about 0.1 to 10 MPa.

電解質膜としては、通常、固体高分子型燃料電池に使用されているものが挙げられ、例えば、パーフルオロスルホン酸樹脂、及び炭化水素系樹脂等のプロトン伝導性樹脂が用いられる。具体的には、スルホン酸基、カルボン酸基及びリン酸基等のプロトン伝導性を有する基を含有する高分子固体電解質等が挙げられる。   Examples of the electrolyte membrane generally include those used in polymer electrolyte fuel cells. For example, proton conductive resins such as perfluorosulfonic acid resins and hydrocarbon resins are used. Specifically, a polymer solid electrolyte containing a proton conductive group such as a sulfonic acid group, a carboxylic acid group, and a phosphoric acid group can be used.

このようにして得られる本発明の膜/電極接合体は、触媒層内に形成される多孔質構造により、高い保水性と排水性を同時に実現させたものであり、優れた発電特性を示す。その高い保水性により、触媒層は高い湿潤状態を保持するため、プロトン伝導性に優れた触媒層となり、さらには触媒層の高い湿潤状態に伴って、電解質膜の乾燥も防止される。一方、本発明の触媒層は優れた排水性を有することから、触媒層中の余分な水分に起因するフラッディングの発生を阻止することができる。そのため、プロトンの移動に同伴する水分に加えて電池反応により水が生成する空気極において、本発明による高い効果が期待される。しかも、上記多孔質構造中の間隙は、プロトン伝導性電解質ナノ粒子の粒径及び量を調節することにより制御することが可能であり、多孔質構造により得られる特性を燃料電池の作動環境に合わせて最適化することができる。   The membrane / electrode assembly of the present invention thus obtained realizes high water retention and drainage simultaneously by the porous structure formed in the catalyst layer, and exhibits excellent power generation characteristics. Due to the high water retention, the catalyst layer maintains a high wet state, so that the catalyst layer becomes excellent in proton conductivity, and further, the electrolyte membrane is prevented from being dried along with the high wet state of the catalyst layer. On the other hand, since the catalyst layer of the present invention has excellent drainage, it is possible to prevent the occurrence of flooding due to excess water in the catalyst layer. Therefore, the high effect by this invention is anticipated in the air electrode which produces | generates water by a battery reaction in addition to the water accompanying the movement of a proton. In addition, the gap in the porous structure can be controlled by adjusting the particle size and amount of the proton conductive electrolyte nanoparticles, and the characteristics obtained by the porous structure are matched to the operating environment of the fuel cell. Can be optimized.

従って、本発明の膜/電極接合体を固体高分子型燃料電池に用いることで、優れた発電特性を有する燃料電池を提供することが可能となる。特に、触媒層中に分散されるプロトン伝導性電解質ナノ粒子中に、プロトン伝導性官能基を導入したエンジニアリングプラスチックのようなプロトン伝導性耐熱性樹脂を含有させることにより、高温域の作動環境における長期間の連続運転の際にも、安定した発電性能を有する。   Therefore, by using the membrane / electrode assembly of the present invention for a polymer electrolyte fuel cell, it is possible to provide a fuel cell having excellent power generation characteristics. In particular, the proton conductive electrolyte nanoparticles dispersed in the catalyst layer contain a proton conductive heat-resistant resin such as an engineering plastic into which proton conductive functional groups have been introduced, thereby improving the operating environment in a high temperature range. It has stable power generation performance even during continuous operation for a period.

以下、本発明を実施例に基づいて説明する。   Hereinafter, the present invention will be described based on examples.

(実施例1)
<プロトン伝導性電解質ナノ粒子の合成>
(1)スルホン化4,4’−ジアミノジフェニルエーテルの合成
500mlの3口フラスコに4,4’−ジアミノフェニルエーテル0.1molを入れ、ゆっくりと濃硫酸17mlを滴下し、窒素雰囲気下、氷浴で2時間攪拌した。その後、発煙硫酸35mlをゆっくりと滴下し、80℃まで昇温した後、2時間攪拌した。反応溶液を室温まで冷却した後、溶液を氷水中にゆっくりと滴下した。得られた白色沈殿物を濾過後、水酸化ナトリウム溶液中で1時間攪拌し、再度濾過した。白色沈殿物を希塩酸溶液中で1時間攪拌した後、水、メタノールで洗浄した。再び、濾過後、室温で24時間減圧乾燥を行うことで、スルホン化4,4’−ジアミノジフェニルエーテルを得た。
(Example 1)
<Synthesis of proton conductive electrolyte nanoparticles>
(1) Synthesis of sulfonated 4,4′-diaminodiphenyl ether 0.1 mol of 4,4′-diaminophenyl ether was placed in a 500 ml three-necked flask, and 17 ml of concentrated sulfuric acid was slowly added dropwise in an ice bath under a nitrogen atmosphere. Stir for 2 hours. Thereafter, 35 ml of fuming sulfuric acid was slowly added dropwise, and the temperature was raised to 80 ° C., followed by stirring for 2 hours. After the reaction solution was cooled to room temperature, the solution was slowly dropped into ice water. The resulting white precipitate was filtered, stirred in sodium hydroxide solution for 1 hour, and filtered again. The white precipitate was stirred in dilute hydrochloric acid solution for 1 hour, and then washed with water and methanol. After filtration again, sulfonated 4,4′-diaminodiphenyl ether was obtained by drying under reduced pressure at room temperature for 24 hours.

(2)ポリイミドナノ粒子の合成
上記(1)で得られたスルホン化4,4’−ジアミノジフェニルエーテル0.05molを3口フラスコに入れ、そこにN,N’−ジメチルアセトアミド500mlを加えて窒素雰囲気下、室温で24時間攪拌した。この反応溶液をシクロヘキサン/二硫化炭素混合溶媒(重量比1:1)に滴下し、ポリアミック酸ナノ粒子分散液を得た。イミド化するためにポリアミック酸ナノ粒子分散液10mlに脱水環化試薬であるピリジン/無水酢酸混合物(重量比1:1)を100ml加え、2時間程室温で攪拌した。濾過後、室温で24時間減圧乾燥を行うことで、スルホン化したポリイミドナノ粒子を得た。
(2) Synthesis of polyimide nanoparticles 0.05 mol of the sulfonated 4,4′-diaminodiphenyl ether obtained in (1) above was placed in a three-necked flask, and 500 ml of N, N′-dimethylacetamide was added to the nitrogen atmosphere. The mixture was stirred at room temperature for 24 hours. The reaction solution was added dropwise to a cyclohexane / carbon disulfide mixed solvent (weight ratio 1: 1) to obtain a polyamic acid nanoparticle dispersion. To imidize, 100 ml of a pyridine / acetic anhydride mixture (1: 1 by weight) as a dehydrating cyclization reagent was added to 10 ml of the polyamic acid nanoparticle dispersion, followed by stirring at room temperature for about 2 hours. After filtration, sulfonated polyimide nanoparticles were obtained by drying under reduced pressure for 24 hours at room temperature.

<プロトン伝導性電解質ナノ粒子分散液の調製>
上記(2)で得られたポリイミドナノ粒子0.5gを極性溶媒(N−メチルピロリドン)10mlに分散させて分散溶液を調製した。
<Preparation of proton conductive electrolyte nanoparticle dispersion>
A dispersion solution was prepared by dispersing 0.5 g of the polyimide nanoparticles obtained in (2) above in 10 ml of a polar solvent (N-methylpyrrolidone).

<膜/電極接合体の作製>
白金を重量比で30%担持したカーボン1gと得られた分散溶液10mlとを混練し、電極インクを調製した。カーボンクロス(厚み400μm、E−TEK社製)の表面に、白金担持量が0.2mg/cmになるまで、電極インクの塗布・乾燥を繰り返すことによって、電極を形成した。得られた電極2枚で、電極インクの塗布面が電解質膜側となるように電解質膜(厚さ50μm、Nafion 112膜、DuPont製)を挟み、加熱プレス(120℃、圧力0.1MPa)することによって膜/電極接合体とした。
<Preparation of membrane / electrode assembly>
1 g of carbon carrying 30% by weight of platinum and 10 ml of the resulting dispersion were kneaded to prepare an electrode ink. An electrode was formed on the surface of a carbon cloth (thickness 400 μm, manufactured by E-TEK) by repeatedly applying and drying the electrode ink until the amount of platinum supported was 0.2 mg / cm 2 . The two obtained electrodes sandwich an electrolyte membrane (thickness 50 μm, Nafion 112 membrane, manufactured by DuPont) so that the electrode ink application surface is on the electrolyte membrane side, and heat press (120 ° C., pressure 0.1 MPa). Thus, a membrane / electrode assembly was obtained.

(比較例1)
白金を重量比で30%担持したカーボン1gと市販のNafion溶液(Aldrich社製)10mlとを混練し、電極インクを調製した。得られた電極インクを用いて、実施例1と同様の方法により、膜/電極接合体を作製した。
(Comparative Example 1)
1 g of carbon carrying 30% by weight of platinum and 10 ml of a commercially available Nafion solution (manufactured by Aldrich) were kneaded to prepare an electrode ink. Using the obtained electrode ink, a membrane / electrode assembly was prepared in the same manner as in Example 1.

(発電評価試験)
得られた実施例1及び比較例1の膜/電極接合体を用いて、図1に示すような燃料電池評価用単セルを組立て、燃料ガスとして加湿した水素ガス、酸化剤ガスとして加湿した空気ガスを用い、以下の条件で発電試験を行った。結果を図4に示す。
(Power generation evaluation test)
Using the obtained membrane / electrode assembly of Example 1 and Comparative Example 1, a single cell for fuel cell evaluation as shown in FIG. 1 was assembled, and humidified hydrogen gas as fuel gas and humidified air as oxidant gas A power generation test was conducted using gas under the following conditions. The results are shown in FIG.

<試験条件>
燃料ガス(水素ガス):流量0.2L/min、加湿器温度80℃
酸化剤ガス(空気ガス):流量0.5L/min、加湿器温度80℃
圧力:0.2MPa(2ata)
セル温度:80℃
電極面積:13cm
<Test conditions>
Fuel gas (hydrogen gas): flow rate 0.2L / min, humidifier temperature 80 ° C
Oxidant gas (air gas): flow rate 0.5 L / min, humidifier temperature 80 ° C
Pressure: 0.2MPa (2ata)
Cell temperature: 80 ° C
Electrode area: 13 cm 2

粒子化していないプロトン伝導性樹脂を用いた比較例1と比較して、実施例1では、高電流密度域(約1A/cm以上)における発電特性の向上が認められる。これは、電解質成分として触媒層にプロトン伝導性電解質ナノ粒子を分散させることによって、触媒層に多孔質構造が形成され、触媒層において高い湿潤状態が保持されると同時に、フラッディングが解消されることで、反応ガスの拡散性が向上したためと考えられる。 Compared with Comparative Example 1 using a proton conductive resin that has not been granulated, Example 1 shows an improvement in power generation characteristics in a high current density region (about 1 A / cm 2 or more). This is because, by dispersing proton conductive electrolyte nanoparticles in the catalyst layer as an electrolyte component, a porous structure is formed in the catalyst layer, and a high wet state is maintained in the catalyst layer, and at the same time, flooding is eliminated. This is thought to be because the diffusibility of the reaction gas was improved.

(連続発電評価試験)
実施例1及び比較例1の膜/電極接合体を用いて、図1に示すような燃料電池評価用単セルを組立てた。燃料ガスとして低加湿の水素ガス、酸化ガスとして低加湿の空気ガスを用い、以下の条件において電流密度0.5A/cmで連続発電試験を行った。結果を図5示す。
(Continuous power generation evaluation test)
A single cell for fuel cell evaluation as shown in FIG. 1 was assembled using the membrane / electrode assembly of Example 1 and Comparative Example 1. Using a low-humidified hydrogen gas as the fuel gas and a low-humidified air gas as the oxidizing gas, a continuous power generation test was conducted at a current density of 0.5 A / cm 2 under the following conditions. The results are shown in FIG.

<試験条件>
燃料ガス(水素ガス):流量0.2L/min、加湿器温度50℃
酸化剤ガス(空気ガス):流量0.5L/min、加湿器温度50℃
圧力:0.2MPa(2ata)
セル温度:95℃
電極面積:13cm
<Test conditions>
Fuel gas (hydrogen gas): flow rate 0.2L / min, humidifier temperature 50 ° C
Oxidant gas (air gas): flow rate 0.5L / min, humidifier temperature 50 ° C
Pressure: 0.2MPa (2ata)
Cell temperature: 95 ° C
Electrode area: 13 cm 2

発電時間が100時間を過ぎた頃から発電特性の低下が見られた比較例1に対し、実施例1は、作動温度が95℃という高温にもかかわらず、500時間程度の長時間に亘って安定した発電特性を示した。これは、触媒層に分散させたプロトン伝導性電解質ナノ粒子にプロトン伝導性耐熱性樹脂を含有させたことにより、物理的安定性及び化学的安定性が向上し、触媒層中の電解質の劣化が抑制されたためと考えられる。また、低加湿環境においても、0.5A/cmで0.55V程度の発電特性を有することから、本発明の実施例1において得られた触媒層は保水性と耐熱性に優れることが示された。 In contrast to Comparative Example 1 in which the power generation characteristics declined from the time when the power generation time exceeded 100 hours, Example 1 was over a long time of about 500 hours despite the high operating temperature of 95 ° C. It showed stable power generation characteristics. This is because the proton-conductive electrolyte nanoparticles dispersed in the catalyst layer contain a proton-conductive heat-resistant resin, thereby improving physical stability and chemical stability, and reducing the electrolyte in the catalyst layer. It is thought that it was suppressed. Further, even in a low humidified environment, it has a power generation characteristic of about 0.55 V at 0.5 A / cm 2 , so that the catalyst layer obtained in Example 1 of the present invention is excellent in water retention and heat resistance. It was done.

固体高分子型燃料電池の概略を模式的に示した断面図である。It is sectional drawing which showed the outline of the polymer electrolyte fuel cell typically. 本発明に係る燃料電池用電極の触媒層の構造の概略を示す模式図である。It is a schematic diagram which shows the outline of the structure of the catalyst layer of the electrode for fuel cells which concerns on this invention. プロトン伝導性を有する樹脂を溶解させた電解質溶液を用いて作製された従来例の触媒層の構造の概略を示す模式図である。It is a schematic diagram which shows the outline of the structure of the catalyst layer of the prior art example produced using the electrolyte solution in which resin which has proton conductivity was dissolved. 本発明の実施例1と比較例1の膜/電極接合体を用いた燃料電池の発電試験の結果を示す図である。It is a figure which shows the result of the electric power generation test of the fuel cell using the membrane / electrode assembly of Example 1 and Comparative Example 1 of the present invention. 本発明の実施例1と比較例1の膜/電極接合体を用いた燃料電池の連続発電試験の結果を示す図である。It is a figure which shows the result of the continuous electric power generation test of the fuel cell using the membrane / electrode assembly of Example 1 and Comparative Example 1 of the present invention.

符号の説明Explanation of symbols

1…プロトン伝導性電解質膜
2…燃料極触媒層
3…空気極触媒層
4…ガス拡散層
5…ガス拡散層
6…燃料極
7…空気極
8…ガス流路
9…ガス流路
10…セパレータ
11…セパレータ
12…プロトン伝導性電解質ナノ粒子
13…粒子化してないプロトン伝導性電解質
14…触媒活性成分
15…導電性材料粒子
16…電解質膜
DESCRIPTION OF SYMBOLS 1 ... Proton conductive electrolyte membrane 2 ... Fuel electrode catalyst layer 3 ... Air electrode catalyst layer 4 ... Gas diffusion layer 5 ... Gas diffusion layer 6 ... Fuel electrode 7 ... Air electrode 8 ... Gas flow path 9 ... Gas flow path 10 ... Separator DESCRIPTION OF SYMBOLS 11 ... Separator 12 ... Proton conductive electrolyte nanoparticle 13 ... Non-particulated proton conductive electrolyte 14 ... Catalytic active ingredient 15 ... Conductive material particle 16 ... Electrolyte membrane

Claims (6)

触媒粒と、プロトン伝導性電解質ナノ粒子とを分散させてなる触媒層を有する燃料電池用電極。   An electrode for a fuel cell having a catalyst layer in which catalyst particles and proton conductive electrolyte nanoparticles are dispersed. 少なくとも燃料極、プロトン伝導性電解質膜、及び空気極から構成される膜/電極接合体であって、燃料極及び空気極の少なくとも一方が、触媒粒と、プロトン伝導性電解質ナノ粒子とを分散させてなる触媒層を有する膜/電極接合体。   A membrane / electrode assembly comprising at least a fuel electrode, a proton conductive electrolyte membrane, and an air electrode, wherein at least one of the fuel electrode and the air electrode disperses catalyst particles and proton conductive electrolyte nanoparticles. A membrane / electrode assembly having a catalyst layer. 前記プロトン伝導性電解質ナノ粒子が、プロトン伝導性耐熱性樹脂を含有する請求項2に記載の膜/電極接合体。   The membrane / electrode assembly according to claim 2, wherein the proton conductive electrolyte nanoparticles contain a proton conductive heat-resistant resin. 前記プロトン伝導性耐熱性樹脂が、プロトン伝導性官能基を導入したエンジニアリングプラスチックである、請求項3に記載の膜/電極接合体。   The membrane / electrode assembly according to claim 3, wherein the proton conductive heat-resistant resin is an engineering plastic having a proton conductive functional group introduced therein. 前記プロトン伝導性電解質ナノ粒子の平均粒径が50〜300nmである、請求項2乃至4のいずれかに記載の膜/電極接合体。   The membrane / electrode assembly according to any one of claims 2 to 4, wherein the proton conductive electrolyte nanoparticles have an average particle diameter of 50 to 300 nm. 請求項2乃至5のいずれかに記載の膜/電極接合体を備える固体高分子型燃料電池。
A polymer electrolyte fuel cell comprising the membrane / electrode assembly according to any one of claims 2 to 5.
JP2004069240A 2004-03-11 2004-03-11 Electrode for fuel cell, membrane/electrode connected object for fuel cell, and solid polymer fuel cell Withdrawn JP2005259513A (en)

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