JP2009272052A - Membrane electrode assembly, and fuel cell - Google Patents

Membrane electrode assembly, and fuel cell Download PDF

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JP2009272052A
JP2009272052A JP2008118769A JP2008118769A JP2009272052A JP 2009272052 A JP2009272052 A JP 2009272052A JP 2008118769 A JP2008118769 A JP 2008118769A JP 2008118769 A JP2008118769 A JP 2008118769A JP 2009272052 A JP2009272052 A JP 2009272052A
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JP5596277B2 (en
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Tatsuya Kawahara
竜也 川原
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Toyota Motor Corp
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    • Y—GENERAL 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 membrane electrode assembly for a fuel cell equipped with a catalyst layer can avoid occurrence of flooding through durability and high performance as well as improved drainage, whereby making operation possible under a wide range of driving conditions. <P>SOLUTION: At least the catalyst layer 20 on cathode side including the membrane electrode assembly is to be of a 3-layer-construction with a total thickness of 10 to 30 μm. A first layer 21 laid in contact with an electrolyte film has a thickness of 1 to 3 μm, and is to be a layer of high durability as compared with the other two layers; a second layer 22 with the thickness of 3 to 9 μm, is to be a layer excellent in catalytic activity as compared with the other 2 layers; and a third layer 23 laid in contact with a gas diffusion layer is to have a lower catalyst density as compared with the other 2 layers or has no catalyst. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、膜電極接合体およびそれを用いた燃料電池に関する。   The present invention relates to a membrane electrode assembly and a fuel cell using the same.

燃料電池の一形態として固体高分子型燃料電池が知られている。固体高分子型燃料電池は他の形態の燃料電池と比較して作動温度が低く（−３０℃〜１００℃程度）、低コスト、コンパクト化が可能なことから、自動車の動力源等として期待されている。   A solid polymer fuel cell is known as one form of the fuel cell. Solid polymer fuel cells have lower operating temperatures (about -30 ° C to 100 ° C) compared to other types of fuel cells, are low in cost, and can be made compact. ing.

図４に示すように、固体高分子型燃料電池は、膜電極接合体（ＭＥＡ）４を主要な構成要素とし、それをガス流路５を備えたセパレータ６，６で挟持することにより、単セルと呼ばれる１つの燃料電池Ａを形成している。膜電極接合体４は、イオン交換膜である固体高分子電解質膜１の両面にアノード側およびカソード側の触媒層２，２およびガス拡散層３，３を積層した構造を持つ。触媒層２は、触媒粒子を担持した導電性担体と電解質を少なくとも含む触媒混合物で形成される。触媒には主に白金系の金属が用いられ、該触媒を担持する導電性担体にはカーボン粒子が主に用いられる。ガス拡散層３には、主にカーボンペーパーまたはカーボンクロスが用いられる。   As shown in FIG. 4, the polymer electrolyte fuel cell has a membrane electrode assembly (MEA) 4 as a main component, and is sandwiched between separators 6 and 6 each having a gas flow path 5 to provide a single unit. One fuel cell A called a cell is formed. The membrane electrode assembly 4 has a structure in which catalyst layers 2 and 2 and gas diffusion layers 3 and 3 on the anode side and the cathode side are laminated on both surfaces of a solid polymer electrolyte membrane 1 which is an ion exchange membrane. The catalyst layer 2 is formed of a catalyst mixture containing at least an electroconductive carrier carrying catalyst particles and an electrolyte. Platinum-based metals are mainly used for the catalyst, and carbon particles are mainly used for the conductive carrier supporting the catalyst. For the gas diffusion layer 3, carbon paper or carbon cloth is mainly used.

固体高分子型燃料電池において発電は次のようにして進行する。まず、アノード側に供給された燃料ガスに含まれる水素は、触媒粒子により酸化され、プロトンおよび電子となる。次に、生成したプロトンは、アノード側触媒層に含まれる電解質、さらに該触媒層と接触している電解質膜を通り、カソード側触媒層に達する。また、アノード側触媒層で生成した電子は、該触媒層を構成している導電性担体、さらに該触媒層に接触しているガス拡散層、セパレータおよび外部回路を通してカソード側触媒層に達する。そして、カソード側触媒層に達したプロトンおよび電子はカソード側に供給されている酸化剤ガス（例えば空気）に含まれる酸素と反応し水を生成する。   In the polymer electrolyte fuel cell, power generation proceeds as follows. First, hydrogen contained in the fuel gas supplied to the anode side is oxidized by the catalyst particles to become protons and electrons. Next, the generated protons pass through the electrolyte contained in the anode catalyst layer and the electrolyte membrane in contact with the catalyst layer, and reach the cathode catalyst layer. The electrons generated in the anode catalyst layer reach the cathode catalyst layer through the conductive carrier constituting the catalyst layer, the gas diffusion layer in contact with the catalyst layer, the separator, and the external circuit. The protons and electrons that have reached the cathode catalyst layer react with oxygen contained in an oxidant gas (for example, air) supplied to the cathode side to generate water.

高い発電性能を長期にわたって維持できる燃料電池を得るために、従来から多くの技術改良が提案がなされており、その中の１つに、膜電極接合体を構成する触媒層に関する技術改良がある。例えば、導電性担体が担持する触媒粒子を合金化する、あるいは触媒粒子を微粒子化して触媒の電極反応面積を大きくして、高い触媒活性を得ることが行われるが、このようにすると、触媒層の耐久性が低下する問題がある。触媒粒子の粒径を大きくする、あるいは高結晶化した触媒担持カーボンを用いることで触媒層の耐久性を向上させることができるが、いずれも性能に対しての背反がある。このように、触媒層の性能と耐久性は相反する関係にあることから、触媒層を単層構造ではなく、２層構造とすることが提案されている。   In order to obtain a fuel cell capable of maintaining high power generation performance over a long period of time, many technical improvements have been proposed, and one of them is a technical improvement related to the catalyst layer constituting the membrane electrode assembly. For example, the catalyst particles carried by the conductive carrier are alloyed, or the catalyst particles are atomized to increase the electrode reaction area of the catalyst to obtain a high catalyst activity. There is a problem in that the durability of the resin deteriorates. Although the durability of the catalyst layer can be improved by increasing the particle size of the catalyst particles or using highly crystallized catalyst-supported carbon, there is a trade-off between the performances. Thus, since the performance and durability of the catalyst layer are in a contradictory relationship, it has been proposed that the catalyst layer has a two-layer structure instead of a single-layer structure.

例えば、特許文献１には、触媒層を、導電性担体に白金粒子が担持されてなる触媒層と、導電性担体に白金合金粒子が担持されてなる触媒層との２層構造とし、白金粒子が担持されてなる触媒層を電解質膜側として積層することが提案されている。また、特許文献２には、カソード側触媒層を、電解質膜側の触媒層（Ｉ）とガス拡散層側の触媒層（ＩＩ）の２層構造とし、電解質膜側触媒層（Ｉ）に含まれる触媒粒子の平均粒子径（Ｄ１）を、ガス拡散層側触媒層（ＩＩ）に含まれる触媒粒子の平均粒子径（Ｄ２）よりも大きくすることが提案されている。触媒層をこのような２層構造とするすることにより、長期にわたって所望の発電性能を維持することのできる、耐久性に優れる膜電極接合体用の触媒層が得られると記載されている。   For example, in Patent Document 1, the catalyst layer has a two-layer structure of a catalyst layer in which platinum particles are supported on a conductive carrier and a catalyst layer in which platinum alloy particles are supported on a conductive carrier. It has been proposed that a catalyst layer on which is supported is laminated on the electrolyte membrane side. Patent Document 2 discloses that the cathode side catalyst layer has a two-layer structure of a catalyst layer (I) on the electrolyte membrane side and a catalyst layer (II) on the gas diffusion layer side, and is included in the electrolyte membrane side catalyst layer (I). It has been proposed to make the average particle diameter (D1) of the catalyst particles larger than the average particle diameter (D2) of the catalyst particles contained in the gas diffusion layer side catalyst layer (II). It is described that the catalyst layer having such a two-layer structure can provide a catalyst layer for a membrane electrode assembly that can maintain desired power generation performance over a long period of time and has excellent durability.

特開２００６−７９８４０号公報JP 2006-79840 A 特開２００６−７９９１７号公報JP 2006-79917 A

本発明者らは、燃料電池および膜電極接合体等について、多くの実験と研究を継続して行ってきているが、触媒層を上記のように２層構造とすることにより、それぞれに適した触媒層をエリアを限定して配置することが可能となり、耐久性と高性能を両立した触媒層が得られるものの、例えば、そのような２層構造の触媒層を用いた膜電極接合体において、厚さが１０μｍ以下の場合には、高加湿条件では排水能力が不足し、フラッティングによる性能低下が発生することを経験した。それを解消すべく触媒層全体の厚さを厚くすると、低加湿条件でドライアップが発生することも経験した。また、触媒層の厚さを厚くすると、触媒量の増大によって高コストとなる問題も生じる。   The present inventors have continued many experiments and researches on fuel cells, membrane electrode assemblies, etc., and the catalyst layer is suitable for each by having a two-layer structure as described above. Although it becomes possible to place the catalyst layer in a limited area and a catalyst layer having both durability and high performance is obtained, for example, in a membrane electrode assembly using such a two-layer catalyst layer, When the thickness was 10 μm or less, it was experienced that drainage capacity was insufficient under high humidification conditions, and performance degradation due to flatting occurred. We also experienced that when the thickness of the entire catalyst layer was increased to solve this problem, dry-up occurred under low humidification conditions. Further, when the thickness of the catalyst layer is increased, there is a problem that the cost is increased due to an increase in the amount of the catalyst.

本発明は、上記のような事情に鑑みてなされたものであり、燃料電池用の膜電極接合体において、耐久性と高性能とともに、排水性も向上させることでフラッティングが発生するのも回避することができ、それにより幅広い運転条件で動作を可能とした触媒層構造を備えた膜電極接合体、およびそれを用いた燃料電池を開示することを課題とする。   The present invention has been made in view of the above circumstances, and in a membrane electrode assembly for a fuel cell, it is possible to avoid occurrence of flatting by improving drainage as well as durability and high performance. It is an object of the present invention to disclose a membrane electrode assembly having a catalyst layer structure that can be operated under a wide range of operating conditions, and a fuel cell using the membrane electrode assembly.

本発明による膜電極接合体は、触媒粒子を担持した導電性担体と電解質を少なくとも含むカソード側触媒層およびアノード側触媒層が電解質膜の両面に対向して配置され、各触媒層にはガス拡散層が積層されてなる燃料電池用の膜電極接合体において、少なくとも前記カソード側触媒層は３層構造をなしかつ全体の厚さが１０〜３０μｍであり、前記電解質膜に接する第１の層は厚さが１〜３μｍであって他の２層と比較して高耐久性の層であり、中間層である第２の層は厚さが３〜９μｍであって他の２層と比較して触媒活性に優れた層であり、前記ガス拡散層に接する第３の層は他の２層と比較して触媒密度が低いまたは触媒を有しない層であることを特徴とする。   In the membrane electrode assembly according to the present invention, a cathode-side catalyst layer and an anode-side catalyst layer containing at least an electroconductive carrier carrying catalyst particles and an electrolyte are arranged to face both surfaces of the electrolyte membrane, and gas diffusion is performed in each catalyst layer. In the membrane electrode assembly for a fuel cell in which layers are laminated, at least the cathode side catalyst layer has a three-layer structure and the total thickness is 10 to 30 μm, and the first layer in contact with the electrolyte membrane is The thickness is 1 to 3 μm and it is a highly durable layer compared to the other two layers, and the second layer, which is an intermediate layer, is 3 to 9 μm in thickness and compared to the other two layers. The third layer in contact with the gas diffusion layer is a layer having a lower catalyst density or no catalyst compared to the other two layers.

本発明者らの実験によれば、燃料電池の発電反応時において、触媒層における電解質膜から１〜３μｍの厚さ内のエリアにおいて、触媒粒子に係る負荷はそれよりも外側のエリアと比較して高く、そのエリアにおいて触媒の劣化が進行しやすい。また、触媒粒子が触媒として機能を果たしているのは、触媒層における電解質膜から１〜１２μｍの厚さ内がほとんどであり、それよりも外側のエリアに存在する触媒粒子によって発電性能が左右されることはほとんどない。一方、触媒層の厚さが１２μｍ程度より薄い場合には、高加湿条件では排水能力が不足し、フラッティングによる性能低下が発生する。   According to the experiments by the present inventors, during the power generation reaction of the fuel cell, in the area within the thickness of 1 to 3 μm from the electrolyte membrane in the catalyst layer, the load related to the catalyst particles is compared with the area outside it. The catalyst is likely to deteriorate in that area. Further, the catalyst particles function as a catalyst mostly within the thickness of 1 to 12 μm from the electrolyte membrane in the catalyst layer, and the power generation performance is affected by the catalyst particles existing in the area outside the catalyst layer. There is hardly anything. On the other hand, when the thickness of the catalyst layer is thinner than about 12 μm, the drainage capacity is insufficient under high humidification conditions, and the performance is deteriorated due to the flatting.

本発明による少なくともカソード側触媒層は３層構造であり、電解質膜に接する第１の層は厚さが１〜３μｍであって他の２層と比較して高耐久性の層である。そのために、触媒層全体としての高耐久性を確保できる。第２の層は３〜９μｍであり、第１の層と第２の層の厚さの和は、４〜１２μｍである。そして、第２の層は他の２層と比較して触媒活性に優れた層とされており、膜電極接合体としての高い発電性能を確保できる。第３の層は他の２層と比較して触媒密度が低いまたは触媒を有しない層である。それにより、触媒層としての所望の排水性を確保することができ、高加湿条件でフラッティングによる性能低下が発生するのも回避できる。また、第３の層には発電性能そのものは期待しなくてもよく、そのために第３の層は他の２層と比較して触媒密度が低いまたは触媒を有しない層とされる。そのために、高価な触媒の使用量が大きくなることはなく、触媒層の製造コストが高騰することもない。   At least the cathode side catalyst layer according to the present invention has a three-layer structure, and the first layer in contact with the electrolyte membrane has a thickness of 1 to 3 μm and is a highly durable layer compared to the other two layers. Therefore, high durability as the whole catalyst layer can be secured. A 2nd layer is 3-9 micrometers, and the sum of the thickness of a 1st layer and a 2nd layer is 4-12 micrometers. And the 2nd layer is made into the layer excellent in catalyst activity compared with other 2 layers, and can ensure the high electric power generation performance as a membrane electrode assembly. The third layer is a layer having a lower catalyst density or no catalyst compared to the other two layers. Thereby, the desired drainage property as a catalyst layer can be ensured, and it is also possible to avoid the deterioration of performance due to flotation under high humidification conditions. Moreover, the third layer does not have to be expected to have the power generation performance itself. For this reason, the third layer has a lower catalyst density or no catalyst compared to the other two layers. Therefore, the amount of expensive catalyst used is not increased, and the manufacturing cost of the catalyst layer is not increased.

以上のように、本発明によれば、触媒層を３層構造としたことにより、耐久性と高発電効率に加え、フラッティング現象を回避して幅広い運転条件での動作を可能とした膜電極接合体およびそれを用いた燃料電池が得られる。   As described above, according to the present invention, since the catalyst layer has a three-layer structure, in addition to durability and high power generation efficiency, a membrane electrode capable of operating under a wide range of operating conditions by avoiding a flatting phenomenon. A joined body and a fuel cell using the same are obtained.

図１は、本発明による膜電極接合体の一部を示す模式的図である。図１において、１０は電解質膜であり、２０はカソード側の触媒層である。   FIG. 1 is a schematic view showing a part of a membrane electrode assembly according to the present invention. In FIG. 1, 10 is an electrolyte membrane, and 20 is a catalyst layer on the cathode side.

電解質膜１０は、特に限定されず、例えば、デュポン社製の各種のＮａｆｉｏｎ（デュポン社登録商標）やフレミオン（旭硝子社登録商標）に代表されるパーフルオロスルホン酸膜、ダウケミカル社製のイオン交換樹脂、エチレン−四フッ化エチレン共重合体樹脂膜、トリフルオロスチレンをベースポリマーとする樹脂膜などのフッ素系高分子電解質や、スルホン酸基を有する炭化水素系樹脂系膜など、一般的に市販されている固体高分子型電解質膜、高分子微多孔膜に液体電解質を含浸させた膜、多孔質体に高分子電解質を充填させた膜などが挙げられる。電解質膜１０の厚みは、通常、１５〜１５０μｍ程度である。   The electrolyte membrane 10 is not particularly limited. For example, perfluorosulfonic acid membranes typified by various Nafion (registered trademark of DuPont) and Flemion (registered trademark of Asahi Glass) manufactured by DuPont, and ion exchange manufactured by Dow Chemical Co., Ltd. Fluoropolymer electrolytes such as resins, ethylene-tetrafluoroethylene copolymer resin membranes, resin membranes based on trifluorostyrene, and hydrocarbon resin membranes with sulfonic acid groups are generally commercially available. Examples thereof include a solid polymer electrolyte membrane, a membrane in which a polymer microporous membrane is impregnated with a liquid electrolyte, and a membrane in which a porous body is filled with a polymer electrolyte. The thickness of the electrolyte membrane 10 is usually about 15 to 150 μm.

触媒層２０は、全体として１０〜３０μｍの厚さであり、触媒粒子３１と、導電性担体３２と、電解質樹脂（図１では省略している）を少なくとも含む。触媒層２０は３層構造であり、電解質膜１０に接する第１の層２１と、中間層である第２の層２２と、その外側の層であり、図示しないガス拡散層に接する第３の層２３とで構成される。第１の層２１の厚さは１〜３μｍ、第２の層２２の厚さは３〜９μｍである。   The catalyst layer 20 has a thickness of 10 to 30 μm as a whole, and includes at least catalyst particles 31, a conductive carrier 32, and an electrolyte resin (not shown in FIG. 1). The catalyst layer 20 has a three-layer structure, and includes a first layer 21 that is in contact with the electrolyte membrane 10, a second layer 22 that is an intermediate layer, and an outer layer that is in contact with a gas diffusion layer (not shown). Layer 23. The thickness of the first layer 21 is 1 to 3 μm, and the thickness of the second layer 22 is 3 to 9 μm.

前記第１の層２１は、触媒粒子３１を担持した導電性担体３２と電解質とで構成され、かつ第２の層２２および第３の層２３と比較して高耐久性の層である。高耐久性とするための手段は制限されないが、例えば、第１の手段として、図示の例では、第１の層２１は、触媒粒子３１として、第２の層２２および第３の層２３における触媒粒子よりも平均粒径が大きい、平均粒径４ｎｍ以上のものを用いている。   The first layer 21 is composed of a conductive carrier 32 carrying catalyst particles 31 and an electrolyte, and is a highly durable layer compared to the second layer 22 and the third layer 23. The means for achieving high durability is not limited. For example, as the first means, in the illustrated example, the first layer 21 is the catalyst particles 31 in the second layer 22 and the third layer 23. Those having an average particle diameter larger than that of the catalyst particles and having an average particle diameter of 4 nm or more are used.

触媒粒子３１の具体例としては、Ｐｔ、またはＰｔとその他の金属との合金触媒が挙げられる。前記合金触媒として、具体的には、Ｐｔと、ルテニウム、イリジウム、ロジウム、パラジウム、オスミウム、タングステン、鉛、鉄、および金などから選択される少なくとも１種以上の金属との合金などが挙げられる。   Specific examples of the catalyst particles 31 include Pt or an alloy catalyst of Pt and other metals. Specific examples of the alloy catalyst include an alloy of Pt and at least one metal selected from ruthenium, iridium, rhodium, palladium, osmium, tungsten, lead, iron, gold, and the like.

導電性担体３２は、触媒粒子３１を所望の分散状態で担持させるための比表面積を有し、集電体として十分な電子導電性を有しているものであればよく、主成分がカーボンであるのが好ましい。具体的には、カーボンブラック、活性炭、コークス、天然黒鉛、人造黒鉛などからなるカーボン粒子が挙げられる。   The conductive carrier 32 has only to have a specific surface area for supporting the catalyst particles 31 in a desired dispersed state, and has sufficient electronic conductivity as a current collector. The main component is carbon. Preferably there is. Specific examples include carbon particles made of carbon black, activated carbon, coke, natural graphite, artificial graphite and the like.

電解質としては、特に限定されず、上記電解質膜１０に用いたものと同様の固体高分子電解質が挙げられる。   The electrolyte is not particularly limited, and examples thereof include the same solid polymer electrolyte as that used for the electrolyte membrane 10.

第１の層２１において、第２の層２２および第３の層２３と比較して高耐久性の層とするための第２の手段として、触媒粒子３１として、活性種として電位変動に対して溶出し難いＰｔ、もしくはＰｔとの合金触媒を用いるようにしてもよい。具体的な合金として、ＰｔＩｒ、ＰｔＡｕが挙げられる。さらに、第３の手段として、導電性担体３２として結晶性の高いカーボン粒子を用いることも挙げられる。前記第１〜第３の手段は、それぞれ個々に用いてもよく、２つ以上を適宜組み合わせて第１の層２１を形成してもよい。   In the first layer 21, as a second means for making the layer more durable compared to the second layer 22 and the third layer 23, as the catalyst particles 31, as active species, against potential fluctuations Pt which is difficult to elute or an alloy catalyst with Pt may be used. Specific alloys include PtIr and PtAu. Further, as a third means, it is also possible to use carbon particles having high crystallinity as the conductive carrier 32. The first to third means may be used individually, or the first layer 21 may be formed by appropriately combining two or more.

前記第２の層２２は、触媒粒子３１を担持した導電性担体３２と電解質とで構成され、かつ第１の層２１と第３の層２３と比較して触媒活性に優れた層である。触媒活性に優れた層とするための手段は制限されないが、例えば、第１の手段として、図示の例では、第２の層２２は、触媒粒子３１として、第１の層２１における触媒粒子よりも平均粒径が小さい、平均粒径４ｎｍ以下のものを用いている。触媒活性に優れた層とするための第２の手段として、第１の層２１における触媒粒子よりも耐久性は低いが、触媒活性が高い合金触媒、例えばＰｔＦｅ，ＰｔＭｎを用いるようにしてもよい。前記第１の手段と第２の手段の双方を満たす触媒を用いて第２の層２２を形成してもよい。   The second layer 22 is composed of a conductive carrier 32 carrying catalyst particles 31 and an electrolyte, and is a layer having superior catalytic activity as compared with the first layer 21 and the third layer 23. The means for forming a layer having excellent catalytic activity is not limited. For example, as the first means, in the illustrated example, the second layer 22 is used as the catalyst particles 31 than the catalyst particles in the first layer 21. Also, those having a small average particle diameter and an average particle diameter of 4 nm or less are used. As a second means for forming a layer having excellent catalytic activity, an alloy catalyst having a lower catalytic activity than the catalyst particles in the first layer 21 but having a high catalytic activity, such as PtFe or PtMn, may be used. . The second layer 22 may be formed using a catalyst that satisfies both the first means and the second means.

第２の層２２において、導電性担体３２は第１の層２１で使用した導電性担体と同様の導電性担体であってよく、電解質も上記電解質膜１０に用いたものと同様の固体高分子電解質であってよい。   In the second layer 22, the conductive carrier 32 may be the same conductive carrier as that used in the first layer 21, and the electrolyte is a solid polymer similar to that used in the electrolyte membrane 10. It may be an electrolyte.

前記第３の層２３は、前記第１の層２１と第２の層２２と比較して触媒密度が低いまたは触媒を有しない層である。好ましくは第１の層２１と第２の層２２と比較して気孔率が高くされる。この第３の層２３の存在により、触媒層２０内部の総気孔容積が増大し、発電時に発生した生成水による触媒層２０内部の気孔閉鎖によりガス供給不良が発生し難くなると同時に、触媒層２０内部の表面積増大により水蒸気による生成水の持ち出し量が増加する。そのために、触媒層全体として、高耐久性と高性能の双方を満足しながら、さらに高加湿条件で安定的な発電が可能となる。一方、低加湿環境では、触媒層の外側、すなわち第３の層２３から乾燥するために、第３の層２３は機能を停止し、過剰な排水を抑制する。   The third layer 23 is a layer having a lower catalyst density or no catalyst compared to the first layer 21 and the second layer 22. The porosity is preferably higher than that of the first layer 21 and the second layer 22. Due to the presence of the third layer 23, the total pore volume inside the catalyst layer 20 increases, and it becomes difficult for gas supply failure to occur due to pore closure inside the catalyst layer 20 by generated water generated during power generation, and at the same time, the catalyst layer 20 The amount of product water taken out by water vapor increases due to an increase in the internal surface area. Therefore, as a whole catalyst layer, while satisfying both high durability and high performance, it is possible to generate power stably under higher humidification conditions. On the other hand, in the low humidification environment, the third layer 23 stops functioning and suppresses excessive drainage in order to dry from the outside of the catalyst layer, that is, the third layer 23.

好ましくは、前記第３の層２３の触媒密度は、前記導電性担体重量比で４０％以下（０％を含む）であり、それにより、第１の層２１と第２の層２２と比較して触媒密度が低いまたは触媒を有しない層とされる。前記したように、発電性能は第１の層２１と第２の層２２で確保されるので、第３の層２３には発電性能そのものは期待しなくてもよく、そのために第３の層２３の触媒密度を低くすることで、触媒層の製造コストを低くできる効果もある。   Preferably, the catalyst density of the third layer 23 is 40% or less (including 0%) in terms of the weight ratio of the conductive support, thereby comparing with the first layer 21 and the second layer 22. Thus, the layer has a low catalyst density or no catalyst. As described above, since the power generation performance is ensured by the first layer 21 and the second layer 22, the third layer 23 may not expect the power generation performance itself. By lowering the catalyst density, the production cost of the catalyst layer can be reduced.

好ましくは、前記第３の層２３は、導電性担体が撥水性を備える。撥水性の高い導電性担体の一例としてはアセチレンブラックを挙げることができる。通常の導電性担体にＰＴＦＥのような撥水剤を含ませることによって高い撥水性を付与するようにしてもよい。それにより、前記した生成水のコントロールは一層確実となる。また、好ましくは前記第３の層２３は、そこに混合した電解質が第１の層２１および第２の層２２と比較して少ない量とされる。それにより、前記した低湿度環境での自発的な発電機能停止を一層効果的にすることができる。   Preferably, in the third layer 23, the conductive carrier has water repellency. An example of a conductive carrier having high water repellency is acetylene black. High water repellency may be imparted by adding a water repellent such as PTFE to a normal conductive carrier. Thereby, the control of the generated water is further ensured. Preferably, the third layer 23 has a smaller amount of electrolyte mixed therewith than the first layer 21 and the second layer 22. Thereby, the spontaneous power generation function stop in the low humidity environment described above can be made more effective.

なお、第３の層２３において、触媒粒子３１は、使用する場合には第１の層２１または第２の層２２で使用した触媒粒子と同じであってよく、より好ましくは第２の層２２で使用した触媒粒子である。また、導電性担体３２は第１の層２１または第２の層２２で使用した導電性担体と同様の導電性担体であってよく、電解質も上記電解質膜１０に用いたものと同様の固体高分子電解質であってよい。   In the third layer 23, the catalyst particles 31 may be the same as the catalyst particles used in the first layer 21 or the second layer 22 when used, and more preferably the second layer 22. The catalyst particles used in the above. In addition, the conductive carrier 32 may be the same conductive carrier as that used in the first layer 21 or the second layer 22, and the electrolyte has the same solid content as that used in the electrolyte membrane 10. It may be a molecular electrolyte.

図１には示されないが、本発明による膜電極接合体において、アノード側の触媒層は、上記したカソード側の触媒層２０と同じであってもよいが、アノード側では排水性の良否が発電性能に大きな影響を与えることはないので、従来の１層構造または２層構造の触媒層を用いることもできる。また、図４の従来例に基づき説明したと同様に、カソード側触媒層およびアノード側の触媒層の外側にはガス拡散層が積層されて、本発明による燃料電池用の膜電極接合体とされる。さらに、、膜電極接合体をガス流路を備えたセパレータで挟持することにより、単セルと呼ばれる１つの燃料電池が形成される。   Although not shown in FIG. 1, in the membrane electrode assembly according to the present invention, the catalyst layer on the anode side may be the same as the catalyst layer 20 on the cathode side described above. Since the performance is not greatly affected, a conventional catalyst layer having a single-layer structure or a two-layer structure can also be used. Further, as described based on the conventional example of FIG. 4, a gas diffusion layer is laminated outside the cathode side catalyst layer and the anode side catalyst layer to form a membrane electrode assembly for a fuel cell according to the present invention. The Furthermore, one fuel cell called a single cell is formed by sandwiching the membrane electrode assembly with a separator having a gas flow path.

本発明の膜電極接合体で用いるガス拡散層としては、特に限定されないが、カーボンクロスやカーボンペーパーを基材とする層が好ましい。撥水性を高めるために、基材にはＰＴＦＥのような撥水剤が含まれていてもよい。   Although it does not specifically limit as a gas diffusion layer used with the membrane electrode assembly of this invention, The layer which uses a carbon cloth or carbon paper as a base material is preferable. In order to improve water repellency, the substrate may contain a water repellent such as PTFE.

以下、本発明を実施例を用いてより具体的に説明する。なお、本発明は、下記実施例のみに限定されることはない。   Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited only to the following Example.

［実施例１］
電解質膜として、厚さ約３０μｍのパーフルオロカーボンスルフォン酸膜を準備した。この電解質膜のカソード側に、触媒粒径６ｎｍのＰｔを７０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．２ｍｇＰｔ／ｃｍ２の第１の触媒層を形成した。このときの第１の触媒層の厚さは約２．５μｍであった。 [Example 1]
A perfluorocarbon sulfonic acid film having a thickness of about 30 μm was prepared as an electrolyte film. On the cathode side of the electrolyte membrane, an ink-like mixture obtained by mixing 70% by weight of Pt having a catalyst particle diameter of 6 nm and 70% by weight of ethanol and a solution of perfluorocarbon sulfonic acid in ethanol is screen-printed and dried. A first catalyst layer having a basis weight of 0.2 mg Pt / cm 2 was formed. At this time, the thickness of the first catalyst layer was about 2.5 μm.

次に、この第１の触媒層の上に、触媒粒径４ｎｍのＰｔＣｏ合金（原子比５：１）を５０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．２ｍｇＰｔ／ｃｍ２の第２の触媒層を形成した。このときの第２の触媒層の厚さは約５．５μｍであった。 Next, an ink in which a catalyst-carrying carbon carrying 50% by weight of a PtCo alloy (atomic ratio 5: 1) having a catalyst particle diameter of 4 nm and an ethanol solution of perfluorocarbon sulfonic acid are mixed on the first catalyst layer. The resulting mixture was screen-printed and dried to form a second catalyst layer having a catalyst basis weight of 0.2 mg Pt / cm 2 . At this time, the thickness of the second catalyst layer was about 5.5 μm.

次に、この第２の触媒層の上に、触媒粒径２ｎｍのＰｔを３０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．１ｍｇＰｔ／ｃｍ２の第３の触媒層を形成した。このときの担持カーボンとしては、撥水性の高いアセチレンブラックを使用した。触媒層の厚さはトータルで約１５μｍとなった。 Next, an ink-like mixture obtained by mixing 30% by weight of Pt with a catalyst particle diameter of 2 nm on the second catalyst layer and an ethanol solution of perfluorocarbon sulfonic acid is screen-printed and dried. Thus, a third catalyst layer having a catalyst basis weight of 0.1 mg Pt / cm 2 was formed. As the supported carbon at this time, acetylene black having high water repellency was used. The total thickness of the catalyst layer was about 15 μm.

アノード側の触媒層として、触媒粒径３ｎｍのＰｔを６０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．２ｍｇＰｔ／ｃｍ２の触媒層を形成した。このときのアノード側触媒層の厚さは約４．０μｍであった。 As the catalyst layer on the anode side, the catalyst weight is obtained by screen-printing and drying an ink-like mixture obtained by mixing 60% by weight of Pt having a catalyst particle diameter of 3 nm and ethanol solution of perfluorocarbon sulfonic acid. A catalyst layer of 0.2 mg Pt / cm 2 was formed. The thickness of the anode side catalyst layer at this time was about 4.0 μm.

上記の触媒層付き電解質膜を、ＰＴＦＥで撥水処理した厚さ約２００μｍのカーボンペーパーで挟持し、１２０℃で熱プレスすることで、膜電極接合体とした。   The above electrolyte membrane with a catalyst layer was sandwiched between carbon paper having a thickness of about 200 μm treated with PTFE and subjected to heat press, and heat-pressed at 120 ° C. to obtain a membrane electrode assembly.

［実施例２］
電解質膜として、厚さ約３０μｍのパーフルオロカーボンスルフォン酸膜を準備した。この電解質膜のカソード側に、触媒粒径６ｎｍのＰｔＩｒの合金触媒（原子比３：１）を６０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．１ｍｇＰｔ／ｃｍ２の第１の触媒層を形成した。このときの第１の触媒層の厚さは約２．５μｍであった。 [Example 2]
A perfluorocarbon sulfonic acid film having a thickness of about 30 μm was prepared as an electrolyte film. An ink-like mixture in which 60% by weight of a PtIr alloy catalyst having a catalyst particle diameter of 6 nm (atomic ratio of 3: 1) and an ethanol solution of perfluorocarbon sulfonic acid are mixed on the cathode side of the electrolyte membrane. Was screen-printed and dried to form a first catalyst layer having a basis weight of 0.1 mg Pt / cm 2 . At this time, the thickness of the first catalyst layer was about 2.5 μm.

次に、この第１の触媒層の上に、触媒粒径４ｎｍのＰｔＣｏ合金（原子比５：１）を５０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．３ｍｇＰｔ／ｃｍ２の第２の触媒層を形成した。このときの第２の触媒層の厚さは約８．０μｍであった。 Next, an ink in which a catalyst-carrying carbon carrying 50% by weight of a PtCo alloy (atomic ratio 5: 1) having a catalyst particle diameter of 4 nm and an ethanol solution of perfluorocarbon sulfonic acid are mixed on the first catalyst layer. The resulting mixture was screen-printed and dried to form a second catalyst layer having a catalyst basis weight of 0.3 mg Pt / cm 2 . At this time, the thickness of the second catalyst layer was about 8.0 μm.

次に、この第２の触媒層の上に、触媒粒径２ｎｍのＰｔを３０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．１ｍｇＰｔ／ｃｍ２の第３の触媒層を形成した。このときの担持カーボンとしては、撥水性の高いアセチレンブラックを使用した。触媒層の厚さはトータルで約１７μｍとなった。 Next, an ink-like mixture obtained by mixing 30% by weight of Pt with a catalyst particle diameter of 2 nm on the second catalyst layer and an ethanol solution of perfluorocarbon sulfonic acid is screen-printed and dried. Thus, a third catalyst layer having a catalyst basis weight of 0.1 mg Pt / cm 2 was formed. As the supported carbon at this time, acetylene black having high water repellency was used. The total thickness of the catalyst layer was about 17 μm.

アノード側の触媒層として、触媒粒径３ｎｍのＰｔを６０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．２ｍｇＰｔ／ｃｍ２の触媒層を形成した。このときのアノード側触媒層の厚さは約４．０μｍであった。 As the catalyst layer on the anode side, the catalyst weight is obtained by screen-printing and drying an ink-like mixture obtained by mixing 60% by weight of Pt having a catalyst particle diameter of 3 nm and ethanol solution of perfluorocarbon sulfonic acid. A catalyst layer of 0.2 mg Pt / cm 2 was formed. The thickness of the anode side catalyst layer at this time was about 4.0 μm.

上記の触媒層付き電解質膜を、ＰＴＦＥで撥水処理した厚さ約２００μｍのカーボンペーパーで挟持し、１２０℃で熱プレスすることで、膜電極接合体とした。   The above electrolyte membrane with a catalyst layer was sandwiched between carbon paper having a thickness of about 200 μm treated with PTFE and subjected to heat press, and heat-pressed at 120 ° C. to obtain a membrane electrode assembly.

［比較例１］
第３の触媒層を設けないことを除き実施例１と同じカソード側触媒層をカソード側触媒層とした以外は、実施例１と同様にして膜電極接合体を作成した。 [Comparative Example 1]
A membrane / electrode assembly was prepared in the same manner as in Example 1 except that the same cathode-side catalyst layer as in Example 1 was used as the cathode-side catalyst layer except that the third catalyst layer was not provided.

［比較例２］
電解質膜として、厚さ約３０μｍのパーフルオロカーボンスルフォン酸膜を準備した。この電解質膜のカソード側に、触媒粒径６ｎｍのＰｔを７０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．４ｍｇＰｔ／ｃｍ２の触媒層を形成した。このときの触媒層の厚さは約５．０μｍであった。 [Comparative Example 2]
A perfluorocarbon sulfonic acid film having a thickness of about 30 μm was prepared as an electrolyte film. On the cathode side of the electrolyte membrane, an ink-like mixture obtained by mixing 70% by weight of Pt having a catalyst particle diameter of 6 nm and 70% by weight of ethanol and a solution of perfluorocarbon sulfonic acid in ethanol is screen-printed and dried. A catalyst layer having a basis weight of 0.4 mg Pt / cm 2 was formed. At this time, the thickness of the catalyst layer was about 5.0 μm.

アノード側の触媒層として、実施例１と同一のものを形成した。
上記の触媒層付き電解質膜を、ＰＴＦＥで撥水処理した厚さ約２００μｍのカーボンペーパーで挟持し、１２０℃で熱プレスすることで、膜電極接合体とした。 The same catalyst layer as that of Example 1 was formed on the anode side.
The above electrolyte membrane with a catalyst layer was sandwiched between carbon paper having a thickness of about 200 μm treated with PTFE and subjected to heat press, and heat-pressed at 120 ° C. to obtain a membrane electrode assembly.

［比較例３］
電解質膜として、厚さ約３０μｍのパーフルオロカーボンスルフォン酸膜を準備した。この電解質膜のカソード側に、触媒粒径４ｎｍのＰｔＣｏの合金触媒（原子比５：１）を５０重量％担持した触媒担持カーボンと、パーフルオロカーボンスルフォン酸のエタノール溶液とを混合したインク状の混合物をスクリーン印刷し乾燥することで、触媒目付け０．４ｍｇＰｔ／ｃｍ２の触媒層を形成した。このときの触媒層の厚さは約１１μｍであった。 [Comparative Example 3]
A perfluorocarbon sulfonic acid film having a thickness of about 30 μm was prepared as an electrolyte film. An ink-like mixture in which 50% by weight of a PtCo alloy catalyst (atomic ratio 5: 1) having a catalyst particle diameter of 4 nm is mixed with an ethanol solution of perfluorocarbon sulfonic acid on the cathode side of the electrolyte membrane. Was screen-printed and dried to form a catalyst layer having a catalyst basis weight of 0.4 mg Pt / cm 2 . At this time, the thickness of the catalyst layer was about 11 μm.

アノード側の触媒層として、実施例１と同一のものを形成した。
上記の触媒層付き電解質膜を、ＰＴＦＥで撥水処理した厚さ約２００μｍのカーボンペーパーで挟持し、１２０℃で熱プレスすることで、膜電極接合体とした。 The same catalyst layer as that of Example 1 was formed on the anode side.
The above electrolyte membrane with a catalyst layer was sandwiched between carbon paper having a thickness of about 200 μm treated with PTFE and subjected to heat press, and heat-pressed at 120 ° C. to obtain a membrane electrode assembly.

［評価試験］
実施例１と２、および比較例１、２，３の各膜電極接合体をセパレータで挟持して燃料電池とし、電位変動サイクル数と出力電圧との関係から耐久性を評価した。その結果を図２に示した。また、実施例１と２、および比較例１について、カソード側での加湿露点と出力電圧との関係から加湿条件依存性を評価した。その結果を図３に示した。 [Evaluation test]
The membrane electrode assemblies of Examples 1 and 2 and Comparative Examples 1, 2, and 3 were sandwiched between separators to form fuel cells, and durability was evaluated from the relationship between the number of potential fluctuation cycles and the output voltage. The results are shown in FIG. Moreover, about Example 1 and 2 and the comparative example 1, humidification condition dependence was evaluated from the relationship between the humidification dew point and output voltage by the cathode side. The results are shown in FIG.

図２の結果から、比較例１，２，３では比較例１のものが最もよい初期性能と耐久性を示しており、実施例１と２は、その比較例１とほぼ同等の初期性能と耐久性を示していることがわかる。なお、実施例１と２が比較例１と比較して多少性能が良好なのは、触媒の総量がやや多いためである。そして、図３の結果から、実施例１と２のものは共に、比較例１と比較して、幅の広い条件範囲（カソード加湿露点の幅）で安定作動が可能であることがわかる。   From the results of FIG. 2, in Comparative Examples 1, 2, and 3, the comparative example 1 shows the best initial performance and durability, and Examples 1 and 2 have an initial performance substantially equivalent to that of Comparative Example 1. It turns out that it shows durability. The performance of Examples 1 and 2 is slightly better than that of Comparative Example 1 because the total amount of catalyst is slightly larger. From the results of FIG. 3, it can be seen that both Examples 1 and 2 can be stably operated in a wider range of conditions (the width of the cathode humidification dew point) than in Comparative Example 1.

このことから、本発明による３層構造の触媒層を備えた膜電極接合体を持つ燃料電池は、従来のものと比較して、耐久性と発電性能の双方を同時に満足できることがわかる。   From this, it can be seen that the fuel cell having the membrane electrode assembly provided with the catalyst layer having the three-layer structure according to the present invention can satisfy both the durability and the power generation performance at the same time as compared with the conventional one.

本発明による膜電極接合体の一部を示す模式的図。The schematic diagram which shows a part of membrane electrode assembly by this invention. 実施例と比較例での電位変動サイクル数と出力電圧との関係を示すグラフ。The graph which shows the relationship between the number of potential fluctuation cycles and output voltage in an Example and a comparative example. 実施例と比較例でのカソード側での加湿露点と出力電圧との関係を示すグラフ。The graph which shows the relationship between the humidification dew point on the cathode side in an Example and a comparative example, and an output voltage. 固体高分子型燃料電池を説明するための模式図。The schematic diagram for demonstrating a polymer electrolyte fuel cell.

符号の説明Explanation of symbols

１０…電解質膜、２０…カソード側の触媒層、２１…第１の層、２２…第２の層、２３…第３の層、３１…触媒粒子、３２…導電性担体   DESCRIPTION OF SYMBOLS 10 ... Electrolyte membrane, 20 ... Cathode side catalyst layer, 21 ... 1st layer, 22 ... 2nd layer, 23 ... 3rd layer, 31 ... Catalyst particle, 32 ... Conductive carrier

Claims (7)

触媒粒子を担持した導電性担体と電解質を少なくとも含むカソード側触媒層およびアノード側触媒層が電解質膜の両面に対向して配置され、各触媒層にはガス拡散層が積層されてなる燃料電池用の膜電極接合体において、
少なくとも前記カソード側触媒層は３層構造をなしかつ全体の厚さが１０〜３０μｍであり、前記電解質膜に接する第１の層は厚さが１〜３μｍであって他の２層と比較して高耐久性の層であり、中間層である第２の層は厚さが３〜９μｍであって他の２層と比較して触媒活性に優れた層であり、前記ガス拡散層に接する第３の層は他の２層と比較して触媒密度が低いまたは触媒を有しない層であることを特徴とする膜電極接合体。 For a fuel cell, a cathode-side catalyst layer and an anode-side catalyst layer containing at least an electroconductive carrier supporting catalyst particles and an electrolyte are arranged opposite to both surfaces of the electrolyte membrane, and a gas diffusion layer is laminated on each catalyst layer. In the membrane electrode assembly of
At least the cathode side catalyst layer has a three-layer structure and the total thickness is 10 to 30 μm, and the first layer in contact with the electrolyte membrane has a thickness of 1 to 3 μm and is compared with the other two layers. The second layer as an intermediate layer is a layer having a thickness of 3 to 9 μm and excellent in catalytic activity as compared with the other two layers, and is in contact with the gas diffusion layer. A membrane electrode assembly, wherein the third layer is a layer having a lower catalyst density or no catalyst compared to the other two layers. 前記第１の層は、触媒粒子が平均粒径が４ｎｍ以上であるか、導電性担体が結晶性の高いカーボンであるか、または活性種として電位変動に対して溶出し難い触媒もしくは合金触媒を用いるか、のいずれかまたはその２以上の組み合わせによって、前記他の２層と比較して高耐久性の層とされていることを特徴とする請求項１に記載の膜電極接合体。   The first layer includes a catalyst or alloy catalyst in which the catalyst particles have an average particle diameter of 4 nm or more, the conductive carrier is carbon having high crystallinity, or the active species is difficult to elute against potential fluctuations. 2. The membrane / electrode assembly according to claim 1, wherein the membrane / electrode assembly is used as a layer having higher durability compared to the other two layers by using one or a combination of two or more thereof. 前記第２の層は、触媒粒子が平均粒径が４ｎｍ以下であるか、または、触媒活性の高い合金触媒を用いるか、のいずれかまたはその双方によって、前記他の２層と比較して触媒活性に優れた層とされていることを特徴とする請求項１に記載の膜電極接合体。   The second layer has a catalyst particle that has an average particle diameter of 4 nm or less and / or uses an alloy catalyst having a high catalytic activity, or both. The membrane electrode assembly according to claim 1, wherein the membrane electrode assembly is a layer having excellent activity. 前記第３の層は、触媒密度が前記導電性担体重量比で４０％以下であることにより、他の２層と比較して触媒密度が低いまたは触媒を有しない層されていることを特徴とする請求項１に記載の膜電極接合体。   The third layer is a layer having a catalyst density lower than that of the other two layers or having no catalyst when the catalyst density is 40% or less by weight ratio of the conductive support. The membrane electrode assembly according to claim 1. 前記第３の層は、導電性担体が撥水性を備えることを特徴とする請求項１〜４のいずれか１項に記載の膜電極接合体。   The membrane electrode assembly according to any one of claims 1 to 4, wherein the third layer includes a water-repellent conductive carrier. 前記第３の層は、混合した前記電解質が前記第１の層および第２の層と比較して少ない量であることを特徴とする請求項１〜５のいずれか１項に記載の膜電極接合体。   The membrane electrode according to any one of claims 1 to 5, wherein the third layer has a smaller amount of the mixed electrolyte than the first layer and the second layer. Joined body. 請求項１〜６のいずれか１項に記載の膜電極接合体を用いたことを特徴とする燃料電池。   A fuel cell using the membrane electrode assembly according to any one of claims 1 to 6.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011216326A (en) * 2010-03-31 2011-10-27 Equos Research Co Ltd Reaction layer for fuel cell
DE112010002746T5 (en) 2009-06-29 2013-01-24 Kabushiki Kaisha Equos Research Reaction layer for fuel cell
CN113991126A (en) * 2021-10-28 2022-01-28 一汽解放汽车有限公司 Gradient proton exchange membrane fuel cell membrane electrode and preparation method and application thereof
CN115133043A (en) * 2022-07-07 2022-09-30 一汽解放汽车有限公司 Membrane electrode containing gradient cathode catalyst layer and preparation method and application thereof

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE112010002746T5 (en) 2009-06-29 2013-01-24 Kabushiki Kaisha Equos Research Reaction layer for fuel cell
JP2011216326A (en) * 2010-03-31 2011-10-27 Equos Research Co Ltd Reaction layer for fuel cell
CN113991126A (en) * 2021-10-28 2022-01-28 一汽解放汽车有限公司 Gradient proton exchange membrane fuel cell membrane electrode and preparation method and application thereof
CN115133043A (en) * 2022-07-07 2022-09-30 一汽解放汽车有限公司 Membrane electrode containing gradient cathode catalyst layer and preparation method and application thereof

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