JP4889168B2 - Polymer electrolyte fuel cell and polymer electrolyte fuel cell - Google Patents

Polymer electrolyte fuel cell and polymer electrolyte fuel cell Download PDF

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JP4889168B2
JP4889168B2 JP2001252887A JP2001252887A JP4889168B2 JP 4889168 B2 JP4889168 B2 JP 4889168B2 JP 2001252887 A JP2001252887 A JP 2001252887A JP 2001252887 A JP2001252887 A JP 2001252887A JP 4889168 B2 JP4889168 B2 JP 4889168B2
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catalyst layer
electrode catalyst
oxygen electrode
layer
fuel
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JP2003068318A (en
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修 山▲ざき▼
満秋 越後
健 田畑
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Osaka Gas Co Ltd
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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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Description

【０００１】
【発明の属する技術分野】
本発明は、電解質層としての高分子膜の一方の面にその周部を露出する状態で酸素極触媒層を備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層を備えた固体高分子型燃料電池のセル、及び、そのようなセルの複数個にて構成された高分子型燃料電池に関する。
【０００２】
【従来の技術】
かかる固体高分子型燃料電池のセル（以下、単にセルと記載する場合がある）においては、電極触媒を保持した酸素極触媒層及び燃料極触媒層夫々と高分子膜との接触面積を大きくして、発電性能を高くする必要があることから、酸素極触媒層及び燃料極触媒層夫々と高分子膜との接触面積を大きくするために、以下のようにして、高分子膜に対して酸素極触媒層及び燃料極触媒層を接合するものである。
即ち、高分子膜の一方の面にその周部を露出する状態で酸素極触媒層を配置し且つ他方の面にその周部を露出する状態で燃料極触媒層を配置した状態で、高分子膜と各層の重ね方向にホットプレスしてそれらを接合したり、高分子膜と各層の重ね方向に押圧してそれらを接着剤にて接合したりして、酸素極触媒層及び燃料極触媒層夫々と高分子膜との接触面積を大きくするものである。
【０００３】
そして、固体高分子型燃料電池のセルを用いて構成した固体高分子型燃料電池においては、高分子膜厚さ方向に押圧力を印加させることにより、流路形成部材をセルにおける酸素極触媒層の周縁部に対応する外周部に密着させて、セルとの間に酸素極側ガス流路を気密状に形成し、並びに、流路形成部材をセルにおける燃料極触媒層の周縁部に対応する外周部に密着させて、セルとの間に燃料極側ガス流路を気密状に形成している。
【０００４】
従来、高分子膜に酸素極触媒層及び燃料極触媒層を接合するに当たっては、図１９に示すように、面方向の全体にわたって厚さが略均一で且つ強度が略均一に形成した高分子膜１を用い、その高分子膜１の両面に、上述のように酸素極触媒層２ｃと燃料極触媒層３ｃとを振分け配置した状態で、高分子膜１と各層の重ね方向にホットプレスしてそれらを接合したり、高分子膜１と各層の重ね方向に押圧してそれらを接着剤にて接合したりしていた。更に、そのように高分子膜１に酸素極触媒層２ｃ及び燃料極触媒層３ｃを接合して形成した電極―膜接合体における酸素極触媒層２ｃ側にその酸素極触媒層２ｃと同じ大きさの酸素極集電層２ｐを重ねると共に、その酸素極触媒層２ｃ側の矩形枠状の高分子膜１の露出部分に矩形枠状の酸素極側シール材６を重ね、並びに、燃料極触媒層３ｃ側にその燃料極触媒層３ｃと同じ大きさの燃料極集電層３ｐを重ねると共に、その燃料極触媒層３ｃ側の矩形枠状の高分子膜１の露出部分に矩形枠状の燃料極側シール材７を重ねて、セルＣを構成していた。尚、通常は、酸素極触媒層２ｃ及び燃料極触媒層３ｃは高分子膜１よりも硬い材料にて形成され、酸素極集電層２ｐ及び燃料極集電層３ｐは酸素極触媒層２ｃ及び燃料極触媒層３ｃよりも硬い材料（例えばカーボンペーパー等）にて形成される。
【０００５】
図１８は、上述のように構成した従来のセルＣにおける厚さ方向での断面図を示す。つまり、図１８に示すように、上述のように高分子膜１の両面に酸素極触媒層２ｃと燃料極触媒層３ｃとを振分け配置した状態で、高分子膜１と各層の重ね方向に押圧力を印加してそれらを接合することから、高分子膜１において酸素極触媒層２ｃや燃料極触媒層３ｃが重なっている部分は、酸素極触媒層２ｃ及び燃料極触媒層３ｃが重なっていない部分に比べて、膜厚が薄くなる。
【０００６】
そして、従来、固体高分子型燃料電池においては、図２０に示すように、上述のように構成した複数のセルＣを、隣接するセル間に、導電性を有する流路形成部材として酸素極側セパレータ８及び燃料極側セパレータ９を位置させた状態で厚さ方向に並置し、酸素極側セパレータ８をそれに隣接するセルＣにおける酸素極触媒層２ｃの周縁部に対応する外周部に密着させて、セルＣとの間に酸素極側ガス流路ｓを形成し、燃料極側セパレータ９をそれに隣接するセルＣにおける燃料極触媒層３ｃの周縁部に対応する外周部に密着させて、セルＣとの間に燃料極側ガス流路ｆを形成するように構成していた。
【０００７】
つまり、複数のセルＣを上述のように並置した状態で、高分子膜厚さ方向に押圧力を印加させるようにセル並置方向の両側から挟み付けることにより、各セルＣを電気的に接続する接続抵抗を小さくすると共に、酸素極側セパレータ８をそれに隣接するセルＣにおける酸素極触媒層２ｃの周縁部に対応する外周部に密着させ、且つ、燃料極側セパレータ９をそれに隣接するセルＣにおける燃料極触媒層３ｃの周縁部に対応する外周部に密着させて、酸素極側ガス流路ｓ及び燃料極側ガス流路ｆを気密状に形成していた。
【０００８】
【発明が解決しようとする課題】
ところで、固体高分子型燃料電池のセルを用いて構成した固体高分子型燃料電池では、セルに対して、高分子膜厚さ方向に押圧力が印加されることになる。
従来では、酸素極触媒層の周縁部にその酸素極触媒層よりも硬い酸素極集電層の周縁部が重なり、且つ、燃料極触媒層の周縁部にその燃料極触媒層よりも硬い燃料極集電層の周縁部が重なることから、酸素極触媒層の周縁部が酸素極集電層の周縁部に押圧されたり、燃料極触媒層の周縁部が燃料極集電層の周縁部に押圧されたりすることにより、高分子膜においては、酸素極触媒層の周縁部に対応する膜部分（以下、酸素極境界膜部分と称する場合がある）や、燃料極触媒層の周縁部に対応する膜部分（以下、燃料極境界膜部分と称する場合がある）には、他の部分よりも大きい応力がかかり易い。
又、固体高分子型燃料電池のセルは、高分子膜、各触媒層、各集電層というように熱膨張率の異なる部材にて構成されているので、固体高分子型燃料電池においては、高分子膜厚さ方向に押圧力が印加された状態で、起動・停止の繰り返しにより昇温・降温が繰り返されると、高分子膜に引っ張り応力や圧縮応力が繰り返し発生する。
【０００９】
しかしながら、従来の固体高分子型燃料電池のセルでは、上述のように、高分子膜において、酸素極触媒層や燃料極触媒層が重なっている部分は、酸素極触媒層及び燃料極触媒層が重なっていない部分に比べて膜厚が薄くなっているので、高分子膜の酸素極境界膜部分又は燃料極境界膜部分は他の部分よりも強度が弱くなっている。
従って、このようなセルを用いて固体高分子型燃料電池を構成すると、高分子膜厚さ方向に印加される押圧力により、高分子膜の酸素極境界膜部分や燃料極境界膜部分に他の部分よりも強い応力がかかったり、起動・停止の繰り返しにより、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりすると、強度が弱くなっている酸素極境界膜部分又は燃料極境界膜部分に、歪みや亀裂等の損傷が生じ易い。
高分子膜の損傷は、発電反応用としての酸素極側ガス又は燃料極側ガスのクロスリークの原因となり、そのようなガスのクロスリークが生じると発電性能が低下することから、従来の固体高分子型燃料電池のセルでは、固体高分子型燃料電池を構成したときの耐久性を向上する上で改善の余地があった。
【００１０】
本発明は、かかる実情に鑑みてなされたものであり、その目的は、固体高分子型燃料電池を構成したときに耐久性に優れる固体高分子型燃料電池のセル及び耐久性に優れる固体高分子型燃料電池を提供することにある。
【００１１】
〔請求項１記載の発明〕
請求項１に記載の固体高分子型燃料電池のセルの特徴構成は、前記酸素極触媒層における前記高分子膜存在側とは反対側又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、弾性変形自在な補強部材が、前記高分子膜の厚さ方向に印加される押圧力により弾性変形して、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する膜部分に応力が集中するのを抑制するように、前記酸素極触媒層又は前記燃料極触媒層の周縁内外にわたる状態で設けられ、さらに、前記酸素極触媒層における前記高分子膜存在側とは反対側、又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、前記酸素極触媒層より大きな酸素極集電層、又は前記燃料極触媒層より大きな燃料極集電層を備え、前記酸素極触媒層の周縁と前記酸素極集電層の周縁、又は前記燃料極触媒層の周縁と前記燃料極集電層の周縁とがずれるように構成され、前記酸素極集電層が前記酸素極触媒層と前記補強部材とに接触、又は前記燃料極集電層が前記燃料極触媒層と前記補強部材とに接触していることにある。
請求項１記載のセルを用いて固体高分子型燃料電池を構成すると、酸素極触媒層における高分子膜存在側とは反対側又は燃料極触媒層における高分子膜存在側とは反対側に、酸素極触媒層又は燃料極触媒層の周縁内外にわたる状態で、弾性変形自在な補強部材が設けられていることから、高分子膜厚さ方向に押圧力が印加されたり、高分子膜厚さ方向に押圧力が印加された状態で起動・停止が繰り返されて、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりしても、補強部材が弾性変形することにより、高分子膜の酸素極境界膜部分や燃料極境界膜部分に応力がかかるのが抑制されるので、高分子膜の酸素極境界膜部分や燃料極境界膜部分が他の部分よりも強度が弱くなっていたとしても、酸素極境界膜部分又は燃料極境界膜部分に歪みや亀裂等の損傷が生じるのが防止される。
従って、固体高分子型燃料電池を構成したときに耐久性に優れる固体高分子型燃料電池のセルを提供することができるようになった。
また、酸素極集電層の周縁と酸素極触媒層の周縁とが重なる場合、又は、燃料極集電層の周縁と燃料極触媒層の周縁とが重なる場合に比べて、高分子膜における電極境界膜部分に印加される応力が一層小さくなる。
【００１２】
〔請求項２記載の発明〕
請求項２に記載の固体高分子型燃料電池のセルの特徴構成は、前記高分子膜と前記酸素極触媒層との間又は前記高分子膜と前記燃料極触媒層との間に、弾性変形自在な補強部材が、前記高分子膜の厚さ方向に印加される押圧力により弾性変形して、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する膜部分に応力が集中するのを抑制するように、前記酸素極触媒層又は前記燃料極触媒層の周縁内外にわたる状態で設けられ、さらに、前記酸素極触媒層における前記高分子膜存在側とは反対側、又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、前記酸素極触媒層より大きな酸素極集電層、又は前記燃料極触媒層より大きな燃料極集電層を備え、前記酸素極触媒層の周縁と前記酸素極集電層の周縁、又は前記燃料極触媒層の周縁と前記燃料極集電層の周縁とがずれるように構成され、前記酸素極集電層が前記酸素極触媒層と前記補強部材とに接触、又は前記燃料極集電層が前記燃料極触媒層と前記補強部材とに接触していることにある。
請求項２記載のセルを用いて固体高分子型燃料電池を構成すると、高分子膜と酸素極触媒層との間又は高分子膜と燃料極触媒層との間に、酸素極触媒層又は燃料極触媒層の周縁内外にわたる状態で、弾性変形自在な補強部材が設けられていることから、高分子膜厚さ方向に押圧力が印加されたり、高分子膜厚さ方向に押圧力が印加された状態で起動・停止が繰り返されて、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりしても、補強部材が弾性変形することにより、高分子膜の酸素極境界膜部分や燃料極境界膜部分に応力がかかるのが抑制されるので、高分子膜の酸素極境界膜部分や燃料極境界膜部分が他の部分よりも強度が弱くなっていたとしても、酸素極境界膜部分又は燃料極境界膜部分に歪みや亀裂等の損傷が生じるのが防止される。
又、高分子膜と酸素極触媒層との間又は高分子膜と燃料極触媒層との間に、弾性変形自在な補強部材を酸素極触媒層又は燃料極触媒層の周縁内外にわたる状態で配置した状態で、高分子膜と各層の重ね方向にホットプレスしてそれらを接合したり、高分子膜と各層の重ね方向に押圧してそれらを接着剤にて接合したりすると、高分子膜の厚さ方向に押圧力が印加される際に補強部材が弾性変形して、高分子膜の酸素極境界膜部分又は燃料極境界膜部分に印加される応力が逃がされるので、応力が集中するのが抑制されることとなり、酸素極境界膜部分や燃料極境界膜部分の強度が弱くなるのを抑制することができる。そして、そのように酸素極境界膜部分や燃料極境界膜部分の強度が弱くなるのを抑制したセルを用いて、固体高分子型燃料電池を構成すると、酸素極境界膜部分又は燃料極境界膜部分に損傷が生じるのを防止する上で、一層好ましいものとなる。
従って、固体高分子型燃料電池を構成したときに耐久性に優れる固体高分子型燃料電池のセルを提供することができるようになった。
また、酸素極集電層の周縁と酸素極触媒層の周縁とが重なる場合、又は、燃料極集電層の周縁と燃料極触媒層の周縁とが重なる場合に比べて、高分子膜における電極境界膜部分に印加される応力が一層小さくなる。
【００１３】
〔請求項３記載の発明〕
請求項３に記載の固体高分子型燃料電池のセルの特徴構成は、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する部分に、繊維状補強材を前記酸素極触媒層又は前記燃料極触媒層の周縁に対して内外方向にわたって混入することにより、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する部分の強度が他の部分よりも強くなるように構成され、さらに、前記酸素極触媒層における前記高分子膜存在側とは反対側、又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、前記酸素極触媒層より大きな酸素極集電層、又は前記燃料極触媒層より大きな燃料極集電層を備え、前記酸素極触媒層の周縁と前記酸素極集電層の周縁、又は前記燃料極触媒層の周縁と前記燃料極集電層の周縁とがずれるように構成され、前記酸素極集電層が前記酸素極触媒層と前記高分子膜における前記酸素極触媒層の周縁部に対応する部分とに接触、又は前記燃料極集電層が前記燃料極触媒層と前記高分子膜における前記燃料極触媒層の周縁部に対応する部分とに接触していることにある。
請求項３に記載の特徴構成によれば、高分子膜における酸素極境界膜部分又は燃料極境界膜部分に、繊維状補強材を酸素極触媒層又は燃料極触媒層の周縁に対して内外方向にわたって混入することにより、高分子膜における酸素極境界膜部分又は燃料極境界膜部分の強度が他の部分よりも強くなるように構成されているので、高分子膜に酸素極触媒層及び燃料極触媒層を接合するときに、高分子膜の両面に酸素極触媒層と燃料極触媒層とを振分け配置した状態で、高分子膜と各層の重ね方向に押圧力が印加されても、それら酸素極境界膜部分や燃料極境界膜部分の強度が弱くなるのが抑制される。
そして、そのようなセルを用いて固体高分子型燃料電池を構成すると、セルの状態で酸素極境界膜部分や燃料極境界膜部分の強度が弱くなるのが抑制されていることに加えて、繊維状補強材によって、高分子膜における酸素極境界膜部分又は燃料極境界膜部分の強度が他の部分よりも強くなるように構成されていることから、高分子膜厚さ方向に押圧力が印加されたり、高分子膜厚さ方向に押圧力が印加された状態で起動・停止が繰り返されて、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりしても、酸素極境界膜部分又は燃料極境界膜部分に歪みや亀裂等の損傷が生じるのが防止される。
従って、固体高分子型燃料電池を構成したときに耐久性に優れる固体高分子型燃料電池のセルを提供することができるようになった。
また、酸素極集電層の周縁と酸素極触媒層の周縁部に対応する部分が重なる場合、又は、燃料極集電層の周縁と燃料極触媒層の周縁部に対応する部分とが重なる場合に比べて、高分子膜における電極境界膜部分に印加される応力が一層小さくなる。
【００１４】
〔請求項４記載の発明〕
請求項４に記載の固体高分子型燃料電池のセルの特徴構成は、前記高分子膜の全体にわたって混入する繊維状補強材の混入率を、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する部分を他の部分よりも高くすることにより、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する部分の強度が他の部分よりも強くなるように構成され、さらに、前記酸素極触媒層における前記高分子膜存在側とは反対側、又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、前記酸素極触媒層より大きな酸素極集電層、又は前記燃料極触媒層より大きな燃料極集電層を備え、前記酸素極触媒層の周縁と前記酸素極集電層の周縁、又は前記燃料極触媒層の周縁と前記燃料極集電層の周縁とがずれるように構成され、前記酸素極集電層が前記酸素極触媒層と前記高分子膜における前記酸素極触媒層の周縁部に対応する部分とに接触、又は前記燃料極集電層が前記燃料極触媒層と前記高分子膜における前記燃料極触媒層の周縁部に対応する部分とに接触していることにある。
請求項４に記載の特徴構成によれば、高分子膜の全体にわたって混入する繊維状補強材の混入率を、高分子膜における酸素極境界膜部分又は燃料極境界膜部分を他の部分よりも高くすることにより、高分子膜における酸素極境界膜部分又は燃料極境界膜部分の強度が他の部分よりも強くなるように構成されているので、高分子膜に酸素極触媒層及び燃料極触媒層を接合するときに、高分子膜の両面に酸素極触媒層と燃料極触媒層とを振分け配置した状態で、高分子膜と各層の重ね方向に押圧力が印加されても、それら酸素極境界膜部分や燃料極境界膜部分の強度が弱くなるのが抑制される。
そして、そのようなセルを用いて固体高分子型燃料電池を構成すると、セルの状態で酸素極境界膜部分や燃料極境界膜部分の強度が弱くなるのが抑制されていることに加えて、繊維状補強材によって、高分子膜における酸素極境界膜部分又は燃料極境界膜部分の強度が他の部分よりも強くなるように構成されていることから、高分子膜厚さ方向に押圧力が印加されたり、高分子膜厚さ方向に押圧力が印加された状態で起動・停止が繰り返されて、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりしても、酸素極境界膜部分又は燃料極境界膜部分に歪みや亀裂等の損傷が生じるのが防止される。
従って、固体高分子型燃料電池を構成したときに耐久性に優れる固体高分子型燃料電池のセルを提供することができるようになった。
また、酸素極集電層の周縁と酸素極触媒層の周縁部に対応する部分が重なる場合、又は、燃料極集電層の周縁と燃料極触媒層の周縁部に対応する部分とが重なる場合に比べて、高分子膜における電極境界膜部分に印加される応力が一層小さくなる。
【００１５】
〔請求項５記載の発明〕
請求項５に記載の固体高分子型燃料電池の特徴構成は、請求項１〜４のいずれか１項に記載の固体高分子型燃料電池のセルの複数が、隣接するセル間に流路形成部材を位置させた状態で、厚さ方向に並置され、
前記流路形成部材が、その一方側に隣接する前記セルにおける前記酸素極触媒層の周縁部に対応する外周部に密着されて、前記セルとの間に酸素極側ガス流路を形成し、他方側に隣接する前記セルにおける前記燃料極触媒層の周縁部に対応する外周部に密着されて、前記セルとの間に燃料極側ガス流路を形成するように構成されていることにある。
請求項５に記載の特徴構成によれば、請求項１〜４のいずれか１項に記載の固体高分子型燃料電池のセルの複数を、隣接するセル間に流路形成部材を位置させて、厚さ方向に並置した状態で、セル並置方向に押圧力を印加させるようにセル並置方向の両側から挟み付けることにより、各セルを電気的に接続する接続抵抗を小さくすると共に、流路形成部材を、その一方側に隣接するセルにおける酸素極触媒層の周縁部に対応する外周部に密着させ、且つ、他方側に隣接するセルにおける燃料極触媒層の周縁部に対応する外周部に密着させて、酸素極側ガス流路及び燃料極側ガス流路を気密状に形成する。
そして、高分子膜厚さ方向に押圧力が印加されたり、高分子膜厚さ方向に押圧力が印加された状態で起動・停止が繰り返されて、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりしても、請求項１〜４のいずれか１項に記載のセルを用いていることにより、以下のようにして、高分子膜の酸素極境界膜部分や燃料極境界膜部分に歪みや亀裂等の損傷が生じるのが防止される。
つまり、請求項１記載のセルを用いた固体高分子型燃料電池では、酸素極触媒層における高分子膜存在側とは反対側又は燃料極触媒層における高分子膜存在側とは反対側に、酸素極触媒層又は燃料極触媒層の周縁内外にわたる状態で、弾性変形自在な補強部材が設けられていることから、高分子膜厚さ方向に押圧力が印加されたり、高分子膜厚さ方向に押圧力が印加された状態で起動・停止が繰り返されて、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりしても、補強部材が弾性変形することにより、高分子膜の酸素極境界膜部分や燃料極境界膜部分に応力がかかるのが抑制されるので、酸素極境界膜部分又は燃料極境界膜部分に損傷が生じるのが防止される。
【００１６】
請求項２記載のセルを用いた固体高分子型燃料電池では、高分子膜と酸素極触媒層との間又は高分子膜と燃料極触媒層との間に、酸素極触媒層又は燃料極触媒層の周縁内外にわたる状態で、弾性変形自在な補強部材が設けられていることから、高分子膜厚さ方向に押圧力が印加されたり、高分子膜厚さ方向に押圧力が印加された状態で起動・停止が繰り返されて、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりしても、補強部材が弾性変形することにより、高分子膜の酸素極境界膜部分や燃料極境界膜部分に応力がかかるのが抑制されるので、酸素極境界膜部分又は燃料極境界膜部分に損傷が生じるのが防止される。
【００１７】
請求項３記載のセルを用いた固体高分子型燃料電池では、高分子膜における酸素極境界膜部分又は燃料極境界膜部分に、繊維状補強材を酸素極触媒層又は燃料極触媒層の周縁に対して内外方向にわたって混入することにより、あるいは、請求項４記載のセルを用いた固体高分子型燃料電池では、高分子膜の全体にわたって混入する繊維状補強材の混入率を、高分子膜における酸素極境界膜部分又は燃料極境界膜部分を他の部分よりも高くなるようすることにより、高分子膜における酸素極境界膜部分又は燃料極境界膜部分の強度が他の部分よりも強くなっているので、高分子膜厚さ方向に押圧力が印加されたり、高分子膜厚さ方向に押圧力が印加された状態で起動・停止が繰り返されて、高分子膜に引っ張り応力や圧縮応力が繰り返しかかったりしても、酸素極境界膜部分又は燃料極境界膜部分に損傷が生じるのが防止される。
従って、耐久性に優れる固体高分子型燃料電池を提供することができるようになった。
【００１８】
【発明の実施の形態】
〔第１実施形態〕
以下、図面に基づいて本発明の第１実施形態を説明する。
先ず、図１及び図２に基づいて、固体高分子型燃料電池のセルＣについて説明する。尚、図１及び図２においては、高分子膜１の厚さ方向に沿う方向での各部の形状を分かり易いようにするために、高分子膜１の厚さ方向に直交する方向に沿う方向での各部の寸法に対する、高分子膜１の厚さ方向に沿う方向での各部の寸法の比率を実際よりも大きくしてある。
【００１９】
セルＣは、電解質層としての高分子膜１の一方の面にその周部を露出する状態で酸素極触媒層２ｃを備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層３ｃを備え、更に、酸素極触媒層２ｃにおける高分子膜存在側とは反対側の面に酸素極集電層２ｐを備え、且つ、燃料極触媒層３ｃにおける高分子膜存在側とは反対側の面に燃料極集電層３ｐを備えて構成してある。そして、酸素極触媒層２ｃと酸素極集電層２ｐにより、酸素極２を構成し、燃料極触媒層３ｃと燃料極集電層３ｐにより燃料極３を構成してある。
【００２０】
第１実施形態においては、酸素極触媒層２ｃにおける高分子膜存在側とは反対側に弾性変形自在な酸素極側補強部材４を、及び、燃料極触媒層３ｃにおける高分子膜存在側とは反対側に弾性変形自在な燃料極側補強部材５を、それぞれが高分子膜１の厚さ方向に印加される押圧力により弾性変形して、高分子膜１における酸素極触媒層２ｃの周縁部に対応する膜部分及び燃料極触媒層３ｃの周縁部に対応する膜部分に応力が集中するのを抑制するように、それぞれ酸素極触媒層２ｃの周縁内外にわたる状態、燃料極触媒層３ｃの周縁内外にわたる状態で設けてある。
【００２１】
又、酸素極集電層２ｐは、平面形状が酸素極触媒層２ｃよりも大きくなるように形成して、その酸素極集電層２ｐを酸素極触媒層２ｃにおける高分子膜存在側とは反対側の面に、その酸素極触媒層２ｃの周部を全周にわたって覆う状態で、且つ、高分子膜１の周部を全周にわたって露出する状態で備え、並びに、燃料極集電層３ｐも、平面形状が燃料極触媒層３ｃよりも大きくなるように形成して、その燃料極集電層３ｐを燃料極触媒層３ｃにおける高分子膜存在側とは反対側の面に、その燃料極触媒層３ｃの周部を全周にわたって覆う状態で、且つ、高分子膜１の周部を全周にわたって露出する状態で備えてある。
【００２２】
説明を加えると、高分子膜１は矩形状であり、酸素極触媒層２ｃと燃料極触媒層３ｃは、互いに同一の矩形状であり、高分子膜１よりも小さく、又、酸素極集電層２ｐと燃料極集電層３ｐは、互いに同一の矩形状であり、酸素極触媒層２ｃ及び燃料極触媒層３ｃよりも大きい。そして、酸素極触媒層２ｃと燃料極触媒層３ｃは、高分子膜１に対して面対称となるように配置し、並びに、酸素極集電層２ｐと燃料極集電層３ｐとは、高分子膜１に対して面対称となるように配置する。従って、高分子膜１における酸素極触媒層２ｃの周縁部に対応する膜部分、即ち、酸素極境界膜部分、及び、高分子膜１における燃料極触媒層３ｃの周縁部に対応する膜部分、即ち、燃料極境界膜部分夫々における高分子膜１の面方向における位置は一致するので、以下の説明では、高分子膜１における酸素極境界膜部分及び高分子膜１における燃料極境界膜部分夫々を、高分子膜１における電極境界膜部分１Ｗと称する場合がある。
【００２３】
酸素極側補強部材４と燃料極側補強部材５とは、同一の矩形枠状であり、外周が高分子膜１と同一の矩形状で、内周が酸素極触媒層２ｃ及び燃料極触媒層３ｃよりも小さい矩形状であり、厚さは、酸素極触媒層２ｃ及び酸素極集電層２ｐ夫々の厚さを加えた厚さ（即ち、燃料極触媒層３ｃ及び燃料極集電層３ｐ夫々の厚さを加えた厚さ）よりも薄い。
【００２４】
そして、高分子膜１の両面に酸素極触媒層２ｃと燃料極触媒層３ｃとを振分け配置した状態で、高分子膜１と各層の重ね方向にホットプレスしてそれらを接合して、電極−膜接合体を形成し、続いて、その電極−膜接合体における酸素極触媒層２ｃ側に、酸素極側補強部材４、酸素極集電層２ｐを高分子膜１側から記載順に配置して重ねると共に、酸素極側補強部材４における矩形枠状の露出部分に矩形枠状の酸素極側シール材６を重ね、並びに、電極−膜接合体における燃料極触媒層３ｃ側に、燃料極側補強部材５、燃料極集電層３ｐを高分子膜１側から記載順に配置して重ねると共に、燃料極側補強部材５における矩形枠状の露出部分に矩形枠状の燃料極側シール材７を重ねて配置して、セルＣを構成してある。
【００２５】
酸素極側シール材６及び燃料極側シール材７は、互いに同一の矩形枠状であり、外周が高分子膜１と同一の矩形状で、内周が酸素極集電層２ｐ及び燃料極集電層３ｐの外周と略同一の矩形状である。
【００２６】
尚、図１は、上述のように構成したセルＣに対して、高分子膜１の厚さ方向に押圧力を印加した状態、即ち、後述するセルスタックＮＣにセルＣが組み込まれた状態を示し、押圧力により部材同士の重なり部において各部材が変形している状態を示している。但し、押圧力により各部材が変形する形状は、図１に示す形状に限定されるものではない。
【００２７】
高分子膜１は、プロトン導電性を備えたフッ素樹脂系のイオン交換膜（例えば、Ｎａｆｉｏｎ１１２）にて形成してあり、厚さは、例えば５０μｍである。
酸素極触媒層２ｃ及び燃料極触媒層３ｃは、互いに同様の構成であり、カーボンから成る多孔状の導電材にて形成し、夫々、白金及び白金系合金から成る電極触媒を担持してあり、厚さは、例えば２０μｍ程度である。
酸素極集電層２ｐ及び燃料極集電層３ｐは、互いに同様の構成であり、多孔状の導電材、例えば、カーボンペーパー又はカーボンフェルトにて形成し、撥水剤（ＰＴＦＥ：ポロテトラフルオロエチレン等）にて撥水加工してあり、厚さは、例えば３５０μｍ程度である。
又、酸素極側補強部材４及び燃料極側補強部材５は、互いに同様の構成であり、弾性変形自在で気密性を有する材料、例えば、高分子膜１を形成するのと同一の材料にて形成し、厚さは、例えば高分子膜１と同程度である。
酸素極側シール材６及び燃料極側シール材７は、互いに同様の構成であり、気密性を有する材料、例えば、ＰＴＦＥシートにて形成し、厚さは、例えば２５０μｍ程度である。
【００２８】
次に、図３、及び、図１３ないし図１６に基づいて、上述のセルＣの複数個を用いて構成する固体高分子型燃料電池について説明する。尚、図３、及び、図１３ないし図６においても、図１及び図２と同様に、高分子膜１の厚さ方向に直交する方向に沿う方向での各部の寸法に対する、高分子膜１の厚さ方向に沿う方向での各部の寸法の比率を実際よりも大きくしてある。
固体高分子型燃料電池は、セルスタックＮＣを備えて構成してある。そのセルスタックＮＣは、図１６に示すように、セルＣの複数個を、隣接するセル間に流路形成部材としての酸素極側セパレータ８及び燃料極側セパレータ９を位置させた状態で、厚さ方向に並置し、更に、積層方向の両端部夫々に電力取り出し用の集電部１０及び各流体給排用の端板１１を配置した状態で、セル並置方向に押圧力を印加させるように、セル並置方向の両側から挟持部材（図示省略）にて挟み付けることにより構成してある。
【００２９】
酸素極側セパレータ８は、それに隣接するセルＣにおける酸素極触媒層２ｃの周縁部に対応する外周部に密着されて、セルＣとの間に酸素極側ガス流路ｓを形成するように構成し、燃料極側セパレータ９は、それに隣接するセルＣにおける燃料極触媒層３ｃの周縁部に対応する外周部に密着されて、セルＣとの間に燃料極側ガス流路ｆを形成するように構成してある。
【００３０】
酸素極側セパレータ８及び燃料極側セパレータ９は、カーボンからなる緻密な気密性を有する導電材にて形成してある。
【００３１】
図３、及び、図１３ないし図１５に示すように、酸素極側セパレータ８は、酸素極２側の面に、酸素極側反応用ガスを通流させる酸素極側ガス流路ｓを形成する酸素極側ガス通流溝を形成し、反対側の面に、冷却水流路ｗを形成する冷却水通流溝を形成してある。
燃料極側セパレータ９は、燃料極３側の面に、燃料極側反応用ガスを通流させる燃料極側ガス流路ｆを形成する燃料極側ガス通流溝を形成し、反対側の面に、酸素極側セパレータ８の冷却水通流溝と面対称となる冷却水流路形成用の冷却水通流溝を形成してある。
【００３２】
更に、セルＣ、酸素極側セパレータ８及び燃料極側セパレータ９の夫々には、それらを重ねたときに夫々が積層方向に連なる状態で、厚さ方向に貫通する６個の孔Ｃｈ，８ｈ，９ｈを形成してある。積層方向視において、セルＣ、酸素極側セパレータ８及び燃料極側セパレータ９の夫々に形成する６個の孔Ｃｈ，８ｈ，９ｈのうち、２個は酸素極側ガス流路ｓの通流経路の両端部に各別に重なり、別の２個は燃料極側ガス流路ｆの通流経路の両端部に各別に重なり、残りの２個は冷却水流路ｗの通流経路の両端部に各別に重なる。
【００３３】
従って、セルスタックＮＣには、セルＣ、酸素極側セパレータ８及び燃料極側セパレータ９夫々の孔Ｃｈ，８ｈ，９ｈが積層方向に連なって形成される通路が６本形成されるが、それらのうちの２本は、各酸素極側ガス流路ｓの通流経路の両端部に各別に連通し、別の２本は、各燃料極側ガス流路ｆの通流経路の両端部に各別に連通し、残りの２本は、各冷却水流路ｗの通流経路の両端部に各別に連通している。
尚、各酸素極側ガス流路ｓの通流経路の両端部に各別に連通する２本の通路を、酸素極側連通路Ｔｓと、各燃料極側ガス流路ｆの通流経路の両端部に各別に連通する２本の通路を燃料極側連通路Ｔｆと、各冷却水流路ｗの通流経路の両端部に各別に連通する２本の通路を冷却水側連通路Ｔｗと夫々称する。
【００３４】
更に、図１６に示すように、セルスタックＮＣの積層方向の両端部夫々に端板１１を設けてある。一方の端板１１には、２本の酸素極側連通路Ｔｓのうちの一方の端部に連通接続する酸素極側ガス用接続部１２ｓ、２本の燃料極側連通路Ｔｆのうちの一方の端部に連通接続する燃料極側ガス用接続部１２ｆ、及び、２本の冷却水連通路Ｔｗのうちの一方の端部に連通接続する冷却水用接続部１２ｗを備えてある。又、他方の端板１１には、２本の酸素極側連通路Ｔｓのうちの他方の端部に連通接続する酸素極側ガス用接続部１２ｓ、２本の燃料極側連通路Ｔｆのうちの他方の端部に連通接続する燃料極側ガス用接続部１２ｆ、及び、２本の冷却水連通路Ｔｗのうちの他方の端部に連通接続する冷却水用接続部１２ｗを備えてある。
【００３５】
尚、２個の酸素極側ガス用接続部１２ｓのうち、一方は酸素極側反応用ガスの供給用として、他方は酸素極側反応用ガスの排出用として用い、２個の燃料極側ガス用接続部１２ｆのうち、一方は燃料極側反応用ガスの供給用として、他方は燃料極側反応用ガスの排出用として用い、並びに、２個の冷却水用接続部１２ｗのうち、一方は冷却水の供給用として、他方は冷却水の排出用として用いる。
【００３６】
そして、炭化水素系の原燃料を改質した水素含有ガスを燃料極側反応用ガスとして、加湿器（図示省略）にて加湿した後、供給用の酸素極側ガス用接続部１２ｓからセルスタックＮＣに供給し、並びに、送風機（図示省略）からの空気を酸素極側反応用ガスとして、加湿器（図示省略）にて加湿した後、供給用の燃料極側ガス用接続部１２ｆからセルスタックＮＣに供給する。
並びに、冷却水ポンプ（図示省略）により、冷却水を供給用の冷却水用接続部１２ｗからセルスタックＮＣに供給する。
【００３７】
すると、加湿された酸素極側反応ガスは、図１４及び図１５において実線矢印にて示すように、一方の酸素極側連通路Ｔｓから各セルＣの酸素極側ガス流路ｓに供給され、酸素極側ガス流路ｓを通流してから、他方の酸素極側連通路Ｔｓに流出し、その酸素極側連通路Ｔｓを通流して排出用の酸素極側ガス用接続部１２ｓから排出される。
又、燃料極側反応ガスは、図１４及び図１５において二点鎖線矢印にて示すように、一方の燃料極側連通路Ｔｆから各セルＣの燃料極側ガス流路ｆに供給され、燃料極側ガス流路ｆを通流してから、他方の燃料極側連通路Ｔｆに流出し、その燃料極側連通路Ｔｆを通流して排出用の燃料極側ガス用接続部１２ｆから排出される。
又、冷却水は、図１４及び図１５において一点鎖線矢印にて示すように、一方の冷却水連通路Ｔｗから各セルＣの冷却水流路ｗに供給され、冷却水流路ｗを通流してから、他方の冷却水連通路Ｔｗに流出し、その冷却水連通路Ｔｗを通流して排出用の冷却水用接続部１２ｗから排出される。
【００３８】
そして、各セルＣにおいては、酸素極側反応用ガス及び燃料極側反応用ガス夫々に含まれている水蒸気によって、高分子膜１が湿らされる状態で、酸素極側反応用ガス中の酸素と燃料極側反応用ガス中の水素との電気化学反応により発電される。又、冷却水の通流により、各セルＣの温度が所定の温度に維持される。
【００３９】
上述のように構成したセルスタックＮＣにおいては、セル並置方向に押圧力が印加されることになって、高分子膜１における電極境界膜部分１Ｗには、酸素極触媒層２ｃ、酸素極集電層２ｐ、酸素極側シール材６、燃料極触媒層３ｃ、燃料極集電層３ｐ及び燃料極側シール材７夫々のエッジによって、他の部分よりも応力が印加され易いが、酸素極側補強部材４及び燃料極側補強部材５が弾性変形することにより、高分子膜１における電極境界膜部分１Ｗに応力が印加されるのが抑制され、又、起動・停止が繰り返されて高分子膜１に引っ張り応力や圧縮応力が繰り返しかかっても、酸素極側補強部材４及び燃料極側補強部材５が弾性変形することにより、高分子膜１における電極境界膜部分１Ｗに応力が印加されるのが抑制されるので、高分子膜１における電極境界膜部分１Ｗにクリープ破壊が生じるのが防止される。
しかも、酸素極集電層２ｐを酸素極触媒層２ｃよりも大きくして、酸素極集電層２ｐの周縁と酸素極触媒層２ｃの周縁とをずらし、並びに、燃料極集電層３ｐを燃料極触媒層３ｃよりも大きくして、燃料極集電層３ｐの周縁と燃料極触媒層３ｃの周縁とをずらしてあるので、酸素極集電層２ｐの周縁と酸素極触媒層２ｃの周縁とが重なり、並びに、燃料極集電層３ｐの周縁と燃料極触媒層３ｃの周縁とが重なる場合に比べて、高分子膜１における電極境界膜部分１Ｗに印加される応力が一層小さくなるように構成してある。
【００４０】
以下、上述のように構成した本発明によるセルＣと、図１８及び図１９に示す従来のセルＣとにより、耐久性を比較した結果を説明する。尚、耐久性の比較は、酸素極２側に酸素極側セパレータ５を付設し且つ燃料極３側に燃料極側セパレータ６を付設して、出力電圧が最も高くなるように両側から締め付けた状態の１枚のセルを用いて行った。尚、両方のセルＣ共に、高分子膜１の面積は７５ｍｍ×７５ｍｍであり、酸素極２及び燃料極３の面積は５０ｍｍ×５０ｍｍである。
【００４１】
本発明のセル及び従来のセル夫々について、酸素極側ガス流路ｓ及び燃料極側ガス流路ｆ夫々のガス出口を大気開放させた状態で、酸素極側反応用ガスとして空気を加湿器にて加湿した後、酸素極側ガス流路ｓに供給し、並びに、燃料極側反応用ガスとして純水素ガスを加湿器にて加湿した後、燃料極側ガス流路ｆに供給し、電子負荷装置を用いて、電流密度が３０００Ａ／ｍ2 になるように定電流にて発電させて、出力電圧を測定して、両者で比較した。
尚、セルの温度は、７０°Ｃに維持し、燃料利用率を６０％、空気利用率を４０％に夫々、設定した。
【００４２】
図１７に、本発明のセル及び従来のセルの夫々について、時間経過に伴う出力電圧の変化を示す。
発電開始時点から３５００時間が経過するまでの間は、本発明のセルと従来のセルでは、略同様の低下率で出力電圧が低下するが、３５００時間が経過した頃から、従来のセルの出力電圧の低下率が急激に大きくなるとともに、出力電圧が不安定となり、従来のセルは本発明のセルに比べて大きく性能が低下していることが分かる。
【００４３】
発電開始時点の開回路電圧は、本発明のセル及び従来のセル共に９００ｍＶ以上であり、発電時間が５０００時間経過後の開回路電圧は、本発明のセルは９００ｍＶ以上であったが、従来のセルは８５０ｍＶにまで低下していた。
発電時間が５０００時間経過後、セルを分解して高分子膜１を観察したところ、従来のセルでは、電極境界膜部分１Ｗに亀裂が発生していたことから、その亀裂部分でガスのクロスリークが起こって、出力電圧が低下していたものと考えられる。一方、本発明のセルでは、高分子膜１には異状がなかった。
【００４４】
〔第２実施形態〕
先ず、図４及び図５に基づいて、固体高分子型燃料電池のセルＣについて説明する。尚、図４及び図５においては、図１及び図２と同様に、高分子膜１の厚さ方向に直交する方向に沿う方向での各部の寸法に対する、高分子膜１の厚さ方向に沿う方向での各部の寸法の比率を実際よりも大きくしてある。
【００４５】
セルＣは、電解質層としての高分子膜１の一方の面にその周部を露出する状態で酸素極触媒層２ｃを備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層３ｃを備え、更に、酸素極触媒層２ｃにおける高分子膜存在側とは反対側の面に酸素極集電層２ｐを備え、且つ、燃料極触媒層３ｃにおける高分子膜存在側とは反対側の面に燃料極集電層３ｐを備えて構成してある。そして、酸素極触媒層２ｃと酸素極集電層２ｐにより、酸素極２を構成し、燃料極触媒層３ｃと燃料極集電層３ｐにより燃料極３を構成してある。
【００４６】
第２実施形態においては、高分子膜１と酸素極触媒層２ｃとの間に弾性変形自在な酸素極側補強部材１ｓを、及び、高分子膜１と燃料極触媒層３ｃとの間に弾性変形自在な燃料極側補強部材１ｆを、それぞれが高分子膜１の厚さ方向に印加される押圧力により弾性変形して、高分子膜１における酸素極触媒層２ｃの周縁部及び燃料極触媒層３ｃの周縁部に対応する膜部分に応力が集中するのを抑制するように、それぞれ酸素極触媒層２ｃの周縁内外にわたる状態、燃料極触媒層３ｃの周縁内外にわたる状態で設けてある。
【００４７】
説明を加えると、高分子膜１は矩形状であり、その高分子膜１の酸素極触媒層２ｃ側の面において、酸素極触媒層２ｃの周縁部に対応する四角枠状の膜部分を突起させて、その突起部分を酸素極側補強部材１ｓとして機能させ、並びに、高分子膜１の燃料極触媒層３ｃ側の面において、燃料極触媒層３ｃの周縁部に対応する四角枠状の膜部分を突起させて、その突起部分を燃料極側補強部材１ｆとして機能させるように構成してある。つまり、酸素極側補強部材１ｓ及び燃料極側補強部材１ｆを高分子膜１と一体的に形成してある。尚、酸素極側補強部材１ｓ及び燃料極側補強部材１ｆの幅は、高分子膜１において、酸素極触媒層２ｃ及び燃料極触媒層３ｃの周縁に対応する位置よりも内方から、酸素極集電層２ｐ及び燃料極集電層３ｐの周縁に対応する位置よりも外方にわたるような幅としてある。
【００４８】
高分子膜１、酸素極触媒層２ｃ、燃料極触媒層３ｃ、酸素極集電層２ｐ、燃料極集電層３ｐ、酸素極側シール材６及び燃料極側シール材７それぞれの形状、大きさは、第１実施形態と同様であるので説明を省略する。つまり、第２実施形態においても、第１実施形態と同様に、以下の説明では、高分子膜１における酸素極境界膜部分及び高分子膜１における燃料極境界膜部分夫々を高分子膜１における電極境界膜部分１Ｗと称する場合がある。
【００４９】
そして、高分子膜１の一方側に酸素極触媒層２ｃを配置し、並びに、他方側に燃料極触媒層３ｃを配置した状態で、高分子膜１と各層の重ね方向にホットプレスしてそれらを接合して、電極−膜接合体を形成し、続いて、電極−膜接合体における酸素極触媒層２ｃ側に酸素極集電層２ｐを重ねると共に、その側における矩形枠状の高分子膜１の露出部分に矩形枠状の酸素極側シール材６を重ね、並びに、電極−膜接合体における燃料極触媒層３ｃ側に燃料極集電層３ｐを重ねると共に、その側における矩形枠状の高分子膜１の露出部分に矩形枠状の燃料極側シール材７を重ねて配置して、セルＣを構成してある。
【００５０】
尚、図４は、上述のように構成したセルＣに対して、高分子膜１の厚さ方向に押圧力を印加した状態、即ち、後述するセルスタックＮＣにセルＣが組み込まれた状態を示し、押圧力により部材同士の重なり部において各部材が変形している状態を示している。但し、押圧力により各部材が変形する形状は、図４に示す形状に限定されるものではない。
【００５１】
上述のように高分子膜１の厚さ方向に押圧力を印加してホットプレスによって電極−膜接合体を製作する際には、酸素極触媒層２ｃのエッジや燃料極触媒層３ｃのエッジにより高分子膜１における電極境界膜部分１Ｗに応力が集中するのを、酸素極側補強部材１ｓ及び燃料極側補強部材１ｆが弾性変形することにより抑制することができるので、高分子膜１における電極境界膜部分１Ｗの強度が弱くなるのを抑制することができる。
【００５２】
高分子膜１、酸素極触媒層２ｃ、燃料極触媒層３ｃ、酸素極集電層２ｐ、燃料極集電層３ｐそれぞれの材料、厚さは、第１実施形態と同様である。又、酸素極側補強部材１ｓの厚さ、燃料極側補強部材１ｆの厚さは、それぞれ第１実施形態の酸素極側補強部材４の厚さ、燃料極側補強部材５の厚さと同様である。
【００５３】
図６に、上述のセルＣの複数個を用いて構成した固体高分子型燃料電池の要部の縦断面図を示す。尚、固体高分子型燃料電池を構成するセルスタックＮＣの積層構造、即ち、セルＣの複数個を、隣接するセル間に流路形成部材としての酸素極側セパレータ８及び燃料極側セパレータ９を位置させた状態で、厚さ方向に並置し、更に、積層方向の両端部夫々に電力取り出し用の集電部１０及び各流体給排用の端板１１を配置した状態で、セル並置方向に押圧力を印加させるように、セル並置方向の両側から挟持部材（図示省略）にて挟み付ける構造は、第１実施形態において図１３ないし図１６を用いて説明した構造と同様であるので、説明を省略する。又、図６においても、図１及び図２と同様に、高分子膜１の厚さ方向に直交する方向に沿う方向での各部の寸法に対する、高分子膜１の厚さ方向に沿う方向での各部の寸法の比率を実際よりも大きくしてある。
【００５４】
上述のように構成したセルスタックＮＣにおいては、セル並置方向に押圧力が印加されることになって、高分子膜１における電極境界膜部分１Ｗには、酸素極触媒層２ｃ、酸素極集電層２ｐ、酸素極側シール材６、燃料極触媒層３ｃ、燃料極集電層３ｐ及び燃料極側シール材７夫々のエッジによって、他の部分よりも応力が印加され易いが、酸素極側補強部材１ｓ及び燃料極側補強部材１ｆが弾性変形することにより、高分子膜１における電極境界膜部分１Ｗに応力が印加されるのが抑制され、又、起動・停止が繰り返されて高分子膜１に引っ張り応力や圧縮応力が繰り返しかかっても、酸素極側補強部材１ｓ及び燃料極側補強部材１ｆが弾性変形することにより、高分子膜１における電極境界膜部分１Ｗに応力が印加されるのが抑制されるので、高分子膜１における電極境界膜部分１Ｗにクリープ破壊が生じるのが防止される。
しかも、酸素極集電層２ｐを酸素極触媒層２ｃよりも大きくして、酸素極集電層２ｐの周縁と酸素極触媒層２ｃの周縁とをずらし、並びに、燃料極集電層３ｐを燃料極触媒層３ｃよりも大きくして、燃料極集電層３ｐの周縁と燃料極触媒層３ｃの周縁とをずらしてあるので、酸素極集電層２ｐの周縁と酸素極触媒層２ｃの周縁とが重なり、並びに、燃料極集電層３ｐの周縁と燃料極触媒層３ｃの周縁とが重なる場合に比べて、高分子膜１における電極境界膜部分１Ｗに印加される応力が一層小さくなるように構成してある。
【００５５】
〔第３実施形態〕
先ず、図７及び図８に基づいて、固体高分子型燃料電池のセルＣについて説明する。尚、図７及び図８においては、図１及び図２と同様に、高分子膜１の厚さ方向に直交する方向に沿う方向での各部の寸法に対する、高分子膜１の厚さ方向に沿う方向での各部の寸法の比率を実際よりも大きくしてある。
【００５６】
セルＣは、電解質層としての高分子膜１の一方の面にその周部を露出する状態で酸素極触媒層２ｃを備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層３ｃを備え、更に、酸素極触媒層２ｃにおける高分子膜存在側とは反対側の面に酸素極集電層２ｐを備え、且つ、燃料極触媒層３ｃにおける高分子膜存在側とは反対側の面に燃料極集電層３ｐを備えて構成してある。そして、酸素極触媒層２ｃと酸素極集電層２ｐにより、酸素極２を構成し、燃料極触媒層３ｃと燃料極集電層３ｐにより燃料極３を構成してある。
【００５７】
第３実施形態においては、高分子膜１における酸素極触媒層２ｃの周縁部及び燃料極触媒層３ｃの周縁部に対応する部分に、繊維状補強材１ｒを酸素極触媒層１ｃ及び燃料極触媒層３ｃの周縁に対して内外方向にわたって混入することにより、高分子膜１おける酸素極触媒層２ｃの周縁部又は燃料極触媒層３ｃの周縁部に対応する部分の強度が他の部分よりも強くなるように構成してある。
【００５８】
高分子膜１、酸素極触媒層２ｃ、燃料極触媒層３ｃ、酸素極集電層２ｐ、燃料極集電層３ｐ、酸素極側シール材６及び燃料極側シール材７それぞれの形状、大きさは、第１実施形態と同様であるので説明を省略する。つまり、第３実施形態においても、第１実施形態と同様に、以下の説明では、高分子膜１における酸素極境界膜部分及び高分子膜１における燃料極境界膜部分夫々を高分子膜１における電極境界膜部分１Ｗと称する場合がある。
【００５９】
そして、第３実施形態においては、高分子膜１において矩形枠状の電極境界膜部分１Ｗに、繊維状補強材１ｒを混入することにより、高分子膜１における電極境界膜部分１Ｗを、他よりも強度が強くなるように補強（所謂、フィブリル補強）してある。尚、高分子膜１において繊維状補強材１ｒを混入する範囲は、酸素極触媒層２ｃ及び燃料極触媒層３ｃの周縁に対応する位置よりも内方から、酸素極集電層２ｐ及び燃料極集電層３ｐの周縁に対応する位置よりも外方にわたる範囲としてある。
【００６０】
そして、高分子膜１の一方側に酸素極触媒層２ｃを配置し、並びに、他方側に燃料極触媒層３ｃを配置した状態で、高分子膜１と各層の重ね方向にホットプレスしてそれらを接合して、電極−膜接合体を形成し、続いて、電極−膜接合体における酸素極触媒層２ｃ側に酸素極集電層２ｐを重ねると共に、その側における矩形枠状の高分子膜１の露出部分に矩形枠状の酸素極側シール材６を重ね、並びに、電極−膜接合体における燃料極触媒層３ｃ側に燃料極集電層３ｐを重ねると共に、その側における矩形枠状の高分子膜１の露出部分に矩形枠状の燃料極側シール材７を重ねて配置して、セルＣを構成してある。
【００６１】
尚、図７は、上述のように構成したセルＣに対して、高分子膜１の厚さ方向に押圧力を印加した状態、即ち、後述するセルスタックＮＣにセルＣが組み込まれた状態を示し、押圧力により部材同士の重なり部において各部材が変形している状態を示している。但し、押圧力により各部材が変形する形状は、図７に示す形状に限定されるものではない。
【００６２】
上述のように高分子膜１の厚さ方向に押圧力を印加してホットプレスによって電極−膜接合体を製作する際に、酸素極触媒層２ｃのエッジや燃料極触媒層３ｃのエッジにより高分子膜１における電極境界膜部分１Ｗに応力が集中しても、高分子膜１における電極境界膜部分１Ｗに、繊維状補強材１ｒを混入することにより、電極境界膜部分１Ｗの強度が他の部分よりも強くなるようにしてあるので、高分子膜１における電極境界膜部分１Ｗの強度が弱くなるのを抑制することができる。
【００６３】
高分子膜１、酸素極触媒層２ｃ、燃料極触媒層３ｃ、酸素極集電層２ｐ、燃料極集電層３ｐそれぞれの材料、厚さは、第１実施形態と同様である。
繊維状補強材としては、高分子膜１に悪影響を与えず、固体高分子型燃料電池の運転条件下において安定な種々の繊維状材を用いることが可能であるが、補強作用を一層増大させるには、弾性を有する繊維状材が好ましく、例えば、ＰＴＦＥフィブリル（微小繊維）を用いることができる。
【００６４】
図９に、上述のセルＣの複数個を用いて構成した固体高分子型燃料電池の要部の縦断面図を示す。尚、固体高分子型燃料電池を構成するセルスタックＮＣの積層構造は、第１実施形態において図１３ないし図１６を用いて説明した構造と同様であるので、説明を省略する。又、図９においても、図１及び図２と同様に、高分子膜１の厚さ方向に直交する方向に沿う方向での各部の寸法に対する、高分子膜１の厚さ方向に沿う方向での各部の寸法の比率を実際よりも大きくしてある。
【００６５】
上述のように構成したセルスタックＮＣにおいては、セル並置方向に押圧力が印加されることになって、高分子膜１における電極境界膜部分１Ｗには、酸素極触媒層２ｃ、酸素極集電層２ｐ、酸素極側シール材６、燃料極触媒層３ｃ、燃料極集電層３ｐ及び燃料極側シール材７夫々のエッジによって、他の部分よりも大きい応力が印加されることとなり、又、起動・停止が繰り返されて高分子膜１に引っ張り応力や圧縮応力が繰り返しかかることとなるが、高分子膜１における電極境界膜部分１Ｗを他の部分よりも強度が強くなるように繊維状補強材１ｒにて補強してあるので、電極境界膜部分１Ｗにクリープ破壊が生じるのが防止される。
しかも、酸素極集電層２ｐを酸素極触媒層２ｃよりも大きくして、酸素極集電層２ｐの周縁と酸素極触媒層２ｃの周縁とをずらし、並びに、燃料極集電層３ｐを燃料極触媒層３ｃよりも大きくして、燃料極集電層３ｐの周縁と燃料極触媒層３ｃの周縁とをずらしてあるので、酸素極集電層２ｐの周縁と酸素極触媒層２ｃの周縁とが重なり、並びに、燃料極集電層３ｐの周縁と燃料極触媒層３ｃの周縁とが重なる場合に比べて、高分子膜１における電極境界膜部分１Ｗに印加される応力が一層小さくなるように構成してある。
【００６６】
〔第４実施形態〕
先ず、図１０及び図１１に基づいて、固体高分子型燃料電池のセルＣについて説明する。尚、図１０及び図１１においては、図１及び図２と同様に、高分子膜１の厚さ方向に直交する方向に沿う方向での各部の寸法に対する、高分子膜１の厚さ方向に沿う方向での各部の寸法の比率を実際よりも大きくしてある。
【００６７】
セルＣは、電解質層としての高分子膜１の一方の面にその周部を露出する状態で酸素極触媒層２ｃを備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層３ｃを備え、更に、酸素極触媒層２ｃにおける高分子膜存在側とは反対側の面に酸素極集電層２ｐを備え、且つ、燃料極触媒層３ｃにおける高分子膜存在側とは反対側の面に燃料極集電層３ｐを備えて構成してある。そして、酸素極触媒層２ｃと酸素極集電層２ｐにより、酸素極２を構成し、燃料極触媒層３ｃと燃料極集電層３ｐにより燃料極３を構成してある。
【００６８】
第３実施形態においては、高分子膜１の全体にわたって混入する繊維状補強材１ｒの混入率を、高分子膜１における酸素極触媒層２ｃの周縁部及び燃料極触媒層３ｃの周縁部に対応する部分を他の部分よりも高くすることにより、高分子膜１における酸素極触媒層２ｃの周縁部及び燃料極触媒層３ｃの周縁部に対応する部分の強度が他の部分よりも強くなるように構成してある。尚、高分子膜１において繊維状補強材１ｒの混入率を他の部分よりも高くする範囲は、酸素極触媒層２ｃ及び燃料極触媒層３ｃの周縁に対応する位置よりも内方から、酸素極集電層２ｐ及び燃料極集電層３ｐの周縁に対応する位置よりも外方にわたる範囲としてある。
【００６９】
高分子膜１、酸素極触媒層２ｃ、燃料極触媒層３ｃ、酸素極集電層２ｐ、燃料極集電層３ｐ、酸素極側シール材６及び燃料極側シール材７それぞれの形状、大きさは、第１実施形態と同様であるので説明を省略する。つまり、第４実施形態においても、第１実施形態と同様に、以下の説明では、高分子膜１における酸素極境界膜部分及び高分子膜１における燃料極境界膜部分夫々を高分子膜１における電極境界膜部分１Ｗと称する場合がある。
【００７０】
そして、第４実施形態においては、高分子膜１の全体にわたって繊維状補強材１ｒを混入して、高分子膜１を補強（所謂、フィブリル補強）してあるが、その繊維状補強材１ｒの混入率を、高分子膜１における矩形枠状の電極境界膜部分１Ｗを他の部分よりも高くすることにより、高分子膜１における電極境界膜部分１Ｗを、他よりも強度が強くなるようにしてある。
【００７１】
そして、高分子膜１の一方側に酸素極触媒層２ｃを配置し、並びに、他方側に燃料極触媒層３ｃを配置した状態で、高分子膜１と各層の重ね方向にホットプレスしてそれらを接合して、電極−膜接合体を形成し、続いて、電極−膜接合体における酸素極触媒層２ｃ側に酸素極集電層２ｐを重ねると共に、その側における矩形枠状の高分子膜１の露出部分に矩形枠状の酸素極側シール材６を重ね、並びに、電極−膜接合体における燃料極触媒層３ｃ側に燃料極集電層３ｐを重ねると共に、その側における矩形枠状の高分子膜１の露出部分に矩形枠状の燃料極側シール材７を重ねて配置して、セルＣを構成してある。
【００７２】
尚、図１０は、上述のように構成したセルＣに対して、高分子膜１の厚さ方向に押圧力を印加した状態、即ち、後述するセルスタックＮＣにセルＣが組み込まれた状態を示し、押圧力により部材同士の重なり部において各部材が変形している状態を示している。但し、押圧力により各部材が変形する形状は、図１０に示す形状に限定されるものではない。
【００７３】
上述のように高分子膜１の厚さ方向に押圧力を印加してホットプレスによって電極−膜接合体を製作する際に、酸素極触媒層２ｃのエッジや燃料極触媒層３ｃのエッジにより高分子膜１における電極境界膜部分１Ｗに応力が集中しても、高分子膜１における電極境界膜部分１Ｗの繊維状補強材１ｒの混入率を他の部分よりも高くすることにより、電極境界膜部分１Ｗの強度が他の部分よりも強くなるようにしてあるので、高分子膜１における電極境界膜部分１Ｗの強度が弱くなるのを抑制することができる。
【００７４】
高分子膜１、酸素極触媒層２ｃ、燃料極触媒層３ｃ、酸素極集電層２ｐ、燃料極集電層３ｐそれぞれの材料、厚さは、第１実施形態と同様である。
繊維状補強材としては、第３実施形態において説明したものと同様のものを用いることができる。
【００７５】
図１２に、上述のセルＣの複数個を用いて構成した固体高分子型燃料電池の要部の縦断面図を示す。尚、固体高分子型燃料電池を構成するセルスタックＮＣの積層構造は、第１実施形態において図１３ないし図１６を用いて説明した構造と同様であるので、説明を省略する。又、図１２においても、図１及び図２と同様に、高分子膜１の厚さ方向に直交する方向に沿う方向での各部の寸法に対する、高分子膜１の厚さ方向に沿う方向での各部の寸法の比率を実際よりも大きくしてある。
【００７６】
上述のように構成したセルスタックＮＣにおいては、セル並置方向に押圧力が印加されることになって、高分子膜１における電極境界膜部分１Ｗには、酸素極触媒層２ｃ、酸素極集電層２ｐ、酸素極側シール材６、燃料極触媒層３ｃ、燃料極集電層３ｐ及び燃料極側シール材７夫々のエッジによって、他の部分よりも大きい応力が印加されることとなり、又、起動・停止が繰り返されて高分子膜１に引っ張り応力や圧縮応力が繰り返しかかることとなるが、高分子膜１における電極境界膜部分１Ｗを他の部分よりも強度が強くなるように繊維状補強材１ｒにて補強してあるので、電極境界膜部分１Ｗにクリープ破壊が生じるのが防止される。
しかも、酸素極集電層２ｐを酸素極触媒層２ｃよりも大きくして、酸素極集電層２ｐの周縁と酸素極触媒層２ｃの周縁とをずらし、並びに、燃料極集電層３ｐを燃料極触媒層３ｃよりも大きくして、燃料極集電層３ｐの周縁と燃料極触媒層３ｃの周縁とをずらしてあるので、酸素極集電層２ｐの周縁と酸素極触媒層２ｃの周縁とが重なり、並びに、燃料極集電層３ｐの周縁と燃料極触媒層３ｃの周縁とが重なる場合に比べて、高分子膜１における電極境界膜部分１Ｗに印加される応力が一層小さくなるように構成してある。
【００７７】
〔別実施形態〕
次に別実施形態を説明する。
（イ） 上記の第１及び第２の各実施形態においては、酸素極側補強部材及び燃料極側補強部材の両方を設ける場合について例示したが、酸素極側補強部材及び燃料極側補強部材のうちのいずれか一方のみを設けても良い。
【００７８】
（ロ） 上記の各実施形態においては、高分子膜１における酸素極触媒層２ｃの周縁部に対応する膜部分、即ち、酸素極境界膜部分と、高分子膜１における燃料極触媒層３ｃの周縁部に対応する膜部分、即ち、燃料極境界膜部分とで、高分子膜１の面方向における位置が一致するように構成する場合について例示したが、酸素極境界膜部分と燃料極境界膜部分とで、高分子膜１の面方向における位置が異なるように構成しても良い。
この場合、第１及び第２の各実施形態のように、酸素極側補強部材及び燃料極側補強部材の両方を設けても良いが、酸素極側補強部材及び燃料極側補強部材のうちのいずれか一方のみを設けても良い。
又、高分子膜１における酸素極境界膜部分及び燃料極境界膜部分の両方を他の部分よりも強度が強くなるように繊維状補強材１ｒにて補強しても良いが、高分子膜１における酸素極境界膜部分及び燃料極境界膜部分のうちのいずれか一方のみを他の部分よりも強度が強くなるように繊維状補強材１ｒにて補強しても良い。
【００７９】
（ハ） 上記の各実施形態においては、高分子膜１、酸素極触媒層２ｃ及び燃料極触媒層３ｃをホットプレスしてそれらを接合することにより、電極−膜接合体を形成する場合について例示したが、高分子膜１、酸素極触媒層２ｃ、酸素極集電層２ｐ、燃料極触媒層３ｃ及び燃料極集電層３ｐをホットプレスしてそれらを接合することにより、電極−膜接合体を形成しても良い。
【００８０】
（ニ） 上記の各実施形態において、酸素極シール部材６及び燃料極シール部材７を省略しても良い。その場合、第１実施形態においては、酸素極側セパレータ８をそれに隣接するセルＣの酸素極側補強材４に密着させ、燃料極側セパレータ９をそれに隣接するセルＣの燃料極側補強材５に密着させることになる。又、第２ないし第４の各実施形態においては、酸素極側セパレータ８をそれに隣接するセルＣの高分子膜１の露出部分に密着させ、燃料極側セパレータ９をそれに隣接するセルＣの高分子膜１の露出部分に密着させることになる。
【００８１】
（ホ） 上記の第２実施形態においては、酸素極側補強部材１ｓ及び燃料極側補強部材１ｆを高分子膜１と一体的に形成する場合について例示したが、酸素極側補強部材１ｓ及び燃料極側補強部材１ｆを高分子膜１と別体にしても良い。その場合、酸素極側補強部材１ｓ及び燃料極側補強部材１ｆ夫々の材料は、高分子膜１の材料と異ならせても良い。
【００８２】
（ヘ） 請求項１に記載の特徴構成、請求項２に記載の特徴構成及び請求項３に記載の特徴構成のうちのいずれか二つ、あるいは、全てを組み合わせて、セルＣを構成しても良い。又、請求項１に記載の特徴構成、請求項２に記載の特徴構成及び請求項４に記載の特徴構成のうちのいずれか二つ、あるいは、全てを組み合わせて、セルＣを構成しても良い。
【００８３】
（ト） 高分子膜１を湿らせるための水分をセルＣに供給する形態は、上記の実施形態にて例示した形態、即ち、セルＣに供給する酸素極側反応用ガスや燃料極側反応用ガスを外部に設けた加湿器にて加湿して、それら酸素極側反応用ガスや燃料極側反応用ガスを媒体として水分を供給する形態に限定されるものではない。
例えば、酸素極側セパレータ８及び燃料極側セパレータ９を通水可能な多孔材にて構成すると共に、冷却水流路ｗを通流する冷却水の圧力を、酸素極側ガス流路ｓ及び燃料極側ガス流路ｆ夫々を通流する各反応用ガスの圧力よりも高くして、冷却水流路ｗを通流する冷却水の一部を酸素極側ガス流路ｓ側や燃料極側ガス流路ｆ側に各セパレータ８，９を透過させることにより、セルＣに直接水分を供給する形態としても良い。
【図面の簡単な説明】
【図１】第１実施形態に係る固体高分子型燃料電池のセルの厚さ方向における断面図
【図２】第１実施形態に係る固体高分子型燃料電池のセルの分解斜視図
【図３】第１実施形態に係る固体高分子型燃料電池のセルスタックの要部の横断面図
【図４】第２実施形態に係る固体高分子型燃料電池のセルの厚さ方向における断面図
【図５】第２実施形態に係る固体高分子型燃料電池のセルの分解斜視図
【図６】第２実施形態に係る固体高分子型燃料電池のセルスタックの要部の横断面図
【図７】第３実施形態に係る固体高分子型燃料電池のセルの厚さ方向における断面図
【図８】第３実施形態に係る固体高分子型燃料電池のセルの分解斜視図
【図９】第３実施形態に係る固体高分子型燃料電池のセルスタックの要部の横断面図
【図１０】第４実施形態に係る固体高分子型燃料電池のセルの厚さ方向における断面図
【図１１】第４実施形態に係る固体高分子型燃料電池のセルの分解斜視図
【図１２】第４実施形態に係る固体高分子型燃料電池のセルスタックの要部の横断面図
【図１３】実施形態に係る固体高分子型燃料電池のセルスタックの要部の分解斜視図
【図１４】実施形態に係る固体高分子型燃料電池のセルスタックの要部の分解斜視図
【図１５】実施形態に係る固体高分子型燃料電池のセルスタックの要部の分解斜視図
【図１６】実施形態に係る固体高分子型燃料電池のセルスタックの全体概略構成を示す側面図
【図１７】運転時間経過に伴うセルの出力電圧の変化を示す図
【図１８】従来の固体高分子型燃料電池のセルの厚さ方向における断面図
【図１９】従来の固体高分子型燃料電池のセルの分解斜視図
【図２０】従来の固体高分子型燃料電池のセルスタックの要部の横断面図
【符号の説明】
１ 高分子膜
１ｆ，１ｓ 補強部材
１ｒ 繊維状補強材
２ｃ 酸素極触媒層
３ｃ 燃料極触媒層
４，５ 補強部材
８，９ 流路形成部材
ｆ 燃料極側ガス流路
ｓ 酸素極側ガス流路
Ｃ セル[0001]
BACKGROUND OF THE INVENTION
The present invention comprises an oxygen electrode catalyst layer in a state in which the peripheral portion is exposed on one surface of a polymer film as an electrolyte layer, and a fuel electrode catalyst layer in a state in which the peripheral portion is exposed on the other surface. The present invention relates to a cell of a solid polymer fuel cell and a polymer fuel cell constituted by a plurality of such cells.
[0002]
[Prior art]
In such a polymer electrolyte fuel cell (hereinafter sometimes simply referred to as a cell), the contact area between the polymer electrode and the oxygen electrode catalyst layer holding the electrode catalyst and the fuel electrode catalyst layer is increased. Therefore, in order to increase the contact area between the oxygen electrode catalyst layer and the fuel electrode catalyst layer and the polymer membrane, it is necessary to improve the power generation performance as follows. The electrode catalyst layer and the fuel electrode catalyst layer are joined together.
That is, the oxygen electrode catalyst layer is disposed on one surface of the polymer film with its peripheral portion exposed, and the fuel electrode catalyst layer is disposed on the other surface with its peripheral portion exposed. The oxygen electrode catalyst layer and the fuel electrode catalyst layer can be bonded by hot pressing in the overlapping direction of the membrane and each layer, or by pressing in the overlapping direction of the polymer membrane and each layer and bonding them with an adhesive. The contact area between each polymer film is increased.
[0003]
In the polymer electrolyte fuel cell configured using the cells of the polymer electrolyte fuel cell, the flow path forming member is applied to the oxygen electrode catalyst layer in the cell by applying a pressing force in the polymer film thickness direction. The oxygen electrode side gas flow path is formed in an airtight manner with the cell, and the flow path forming member corresponds to the peripheral part of the fuel electrode catalyst layer in the cell. A fuel electrode-side gas flow path is formed in an airtight manner between the cell and the outer periphery of the cell.
[0004]
Conventionally, when joining an oxygen electrode catalyst layer and a fuel electrode catalyst layer to a polymer membrane, as shown in FIG. 19, a polymer membrane having a substantially uniform thickness and a substantially uniform strength throughout the surface direction. 1 and hot-pressing the polymer membrane 1 and each layer in the overlapping direction with the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c being distributed on both sides of the polymer membrane 1 as described above. They were joined together, or pressed in the overlapping direction of the polymer film 1 and each layer to join them with an adhesive. Further, in the electrode-membrane assembly formed by joining the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c to the polymer membrane 1 on the oxygen electrode catalyst layer 2c side, the same size as the oxygen electrode catalyst layer 2c is formed. The oxygen electrode current collecting layer 2p is stacked, the rectangular frame-shaped oxygen electrode side sealing material 6 is stacked on the exposed portion of the rectangular frame polymer film 1 on the oxygen electrode catalyst layer 2c side, and the fuel electrode catalyst layer A fuel electrode current collecting layer 3p having the same size as the fuel electrode catalyst layer 3c is superimposed on the 3c side, and a rectangular frame-shaped fuel electrode is exposed on the exposed portion of the rectangular frame polymer film 1 on the fuel electrode catalyst layer 3c side. The cell C was configured by overlapping the side sealing material 7. Normally, the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c are formed of a material harder than the polymer film 1, and the oxygen electrode current collector layer 2p and the fuel electrode current collector layer 3p are formed of the oxygen electrode catalyst layer 2c and It is formed of a material harder than the fuel electrode catalyst layer 3c (for example, carbon paper).
[0005]
FIG. 18 is a cross-sectional view in the thickness direction of the conventional cell C configured as described above. That is, as shown in FIG. 18, in a state where the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c are distributed on both surfaces of the polymer film 1 as described above, the polymer film 1 and the layers are pushed in the overlapping direction. Since the pressure is applied to join them, the portion where the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c overlap in the polymer film 1 does not overlap the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c. The film thickness is reduced compared to the portion.
[0006]
Conventionally, in a polymer electrolyte fuel cell, as shown in FIG. 20, the plurality of cells C configured as described above are provided between the adjacent cells as a conductive flow path forming member on the oxygen electrode side. The separator 8 and the fuel electrode side separator 9 are arranged side by side in the thickness direction, and the oxygen electrode side separator 8 is brought into close contact with the outer peripheral portion corresponding to the peripheral portion of the oxygen electrode catalyst layer 2c in the cell C adjacent thereto. An oxygen electrode side gas flow path s is formed between the cell C and the fuel electrode side separator 9 is brought into close contact with the outer peripheral portion corresponding to the peripheral portion of the fuel electrode catalyst layer 3c in the cell C adjacent thereto. The fuel electrode side gas flow path f is formed between the two.
[0007]
That is, with the plurality of cells C juxtaposed as described above, each cell C is electrically connected by being sandwiched from both sides in the cell juxtaposition direction so as to apply a pressing force in the polymer film thickness direction. While reducing the connection resistance, the oxygen electrode side separator 8 is brought into close contact with the outer peripheral portion corresponding to the peripheral portion of the oxygen electrode catalyst layer 2c in the cell C adjacent thereto, and the fuel electrode side separator 9 is connected to the cell C adjacent thereto. The oxygen electrode side gas flow path s and the fuel electrode side gas flow path f are formed in an airtight manner in close contact with the outer peripheral part corresponding to the peripheral part of the fuel electrode catalyst layer 3c.
[0008]
[Problems to be solved by the invention]
By the way, in a polymer electrolyte fuel cell configured using cells of a polymer electrolyte fuel cell, a pressing force is applied to the cell in the polymer film thickness direction.
Conventionally, the peripheral portion of the oxygen electrode catalyst layer is overlapped with the peripheral portion of the oxygen electrode current collecting layer, which is harder than the oxygen electrode catalyst layer, and the peripheral portion of the fuel electrode catalyst layer is harder than the fuel electrode catalyst layer. Since the peripheral part of the current collecting layer overlaps, the peripheral part of the oxygen electrode catalyst layer is pressed against the peripheral part of the oxygen electrode current collector layer, or the peripheral part of the fuel electrode catalyst layer is pressed against the peripheral part of the fuel electrode current collector layer As a result, in the polymer membrane, the membrane portion corresponding to the peripheral portion of the oxygen electrode catalyst layer (hereinafter sometimes referred to as an oxygen electrode boundary membrane portion) or the peripheral portion of the fuel electrode catalyst layer. The membrane portion (hereinafter sometimes referred to as the fuel electrode boundary membrane portion) is likely to be subjected to a larger stress than the other portions.
Further, since the cells of the polymer electrolyte fuel cell are composed of members having different coefficients of thermal expansion such as a polymer membrane, each catalyst layer, and each current collecting layer, in the polymer electrolyte fuel cell, If the temperature rise / fall is repeated by repeated starting and stopping in a state where a pressing force is applied in the polymer film thickness direction, tensile stress and compressive stress are repeatedly generated in the polymer film.
[0009]
However, in the conventional polymer electrolyte fuel cell, as described above, in the polymer membrane, the portion where the oxygen electrode catalyst layer and the fuel electrode catalyst layer overlap each other includes the oxygen electrode catalyst layer and the fuel electrode catalyst layer. Since the film thickness is thinner than the non-overlapping part, the oxygen electrode boundary film part or the fuel electrode boundary film part of the polymer film is weaker than the other parts.
Therefore, when a polymer electrolyte fuel cell is configured using such a cell, the oxygen electrode boundary film part and the fuel electrode boundary film part of the polymer film are not removed by the pressing force applied in the polymer film thickness direction. If tensile stress or compressive stress is repeatedly applied to the polymer film due to repeated start / stop, the oxygen electrode boundary film part or fuel electrode boundary film part is weakened. Damages such as distortion and cracks are likely to occur.
Damage to the polymer film causes cross leakage of oxygen electrode side gas or fuel electrode side gas for power generation reaction, and if such gas cross leakage occurs, power generation performance deteriorates. In the cell of the molecular type fuel cell, there is room for improvement in improving the durability when the polymer electrolyte fuel cell is configured.
[0010]
The present invention has been made in view of such circumstances, and its object is to provide a solid polymer fuel cell having excellent durability when a solid polymer fuel cell is constructed, and a solid polymer having excellent durability. It is to provide a type fuel cell.
[0011]
  [Invention of Claim 1]
  The characteristic configuration of the cell of the solid polymer fuel cell according to claim 1 is that the oxygen electrode catalyst layer is opposite to the polymer film existence side or the fuel electrode catalyst layer is the polymer film existence side. On the opposite side, an elastically deformable reinforcing member is elastically deformed by a pressing force applied in the thickness direction of the polymer membrane, and the peripheral portion of the oxygen electrode catalyst layer or the fuel electrode catalyst in the polymer membrane The oxygen electrode catalyst layer or the fuel electrode catalyst layer is provided in a state extending from the inside to the outside of the periphery so as to suppress stress concentration on the film portion corresponding to the periphery of the layer.Furthermore, an oxygen electrode current collector larger than the oxygen electrode catalyst layer on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or the side opposite to the polymer film existing side in the fuel electrode catalyst layer. Or a fuel electrode current collecting layer larger than the fuel electrode catalyst layer, and a peripheral edge of the oxygen electrode catalyst layer and a peripheral edge of the oxygen electrode current collector layer, or a peripheral edge of the fuel electrode catalyst layer and the fuel electrode current collector layer The oxygen electrode current collecting layer is in contact with the oxygen electrode catalyst layer and the reinforcing member, or the fuel electrode current collecting layer is in contact with the fuel electrode catalyst layer and the reinforcing member. ShiThere is in being.
  When a solid polymer fuel cell is configured using the cell according to claim 1, on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or on the side opposite to the polymer film existing side in the fuel electrode catalyst layer, A reinforcing member that can be elastically deformed is provided in a state that extends inside and outside the periphery of the oxygen electrode catalyst layer or the fuel electrode catalyst layer, so that a pressing force is applied in the polymer film thickness direction or the polymer film thickness direction. Even if the starting and stopping are repeated with the pressing force applied to the polymer film, even if tensile stress or compressive stress is repeatedly applied to the polymer film, the reinforcing member elastically deforms, so that the oxygen electrode boundary of the polymer film Since stress is suppressed on the membrane part and the fuel electrode boundary film part, even if the oxygen electrode boundary film part and the fuel electrode boundary film part of the polymer film are weaker than other parts, oxygen In the pole boundary membrane part or the fuel pole boundary membrane part Miya damage such as a crack of results is prevented.
  Accordingly, it has become possible to provide a polymer electrolyte fuel cell having excellent durability when a polymer electrolyte fuel cell is constructed.
  Further, the electrode in the polymer membrane is compared with the case where the peripheral edge of the oxygen electrode current collecting layer and the peripheral edge of the oxygen electrode catalyst layer overlap, or the case where the peripheral edge of the fuel electrode current collecting layer and the peripheral edge of the fuel electrode catalyst layer overlap. The stress applied to the boundary film portion is further reduced.
[0012]
  [Invention of Claim 2]
  The characteristic configuration of the cell of the solid polymer fuel cell according to claim 2 is characterized in that elastic deformation occurs between the polymer film and the oxygen electrode catalyst layer or between the polymer film and the fuel electrode catalyst layer. The flexible reinforcing member is elastically deformed by the pressing force applied in the thickness direction of the polymer film, and corresponds to the peripheral part of the oxygen electrode catalyst layer or the peripheral part of the fuel electrode catalyst layer in the polymer film. The oxygen electrode catalyst layer or the fuel electrode catalyst layer is provided in a state extending from the inside to the outside of the periphery so as to prevent stress from concentrating on the film portion.Furthermore, an oxygen electrode current collector larger than the oxygen electrode catalyst layer on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or the side opposite to the polymer film existing side in the fuel electrode catalyst layer. Or a fuel electrode current collecting layer larger than the fuel electrode catalyst layer, and a peripheral edge of the oxygen electrode catalyst layer and a peripheral edge of the oxygen electrode current collector layer, or a peripheral edge of the fuel electrode catalyst layer and the fuel electrode current collector layer The oxygen electrode current collecting layer is in contact with the oxygen electrode catalyst layer and the reinforcing member, or the fuel electrode current collecting layer is in contact with the fuel electrode catalyst layer and the reinforcing member. ShiThere is in being.
  When a polymer electrolyte fuel cell is constituted using the cell according to claim 2, an oxygen electrode catalyst layer or a fuel is interposed between the polymer film and the oxygen electrode catalyst layer or between the polymer film and the fuel electrode catalyst layer. Since the elastically deformable reinforcing member is provided in a state extending from the inside and outside of the periphery of the electrode catalyst layer, a pressing force is applied in the polymer film thickness direction or a pressing force is applied in the polymer film thickness direction. Even if the polymer film is repeatedly started and stopped and tensile stress or compressive stress is repeatedly applied to the polymer membrane, the reinforcing member elastically deforms, so that the oxygen electrode boundary membrane portion of the polymer membrane and the fuel electrode boundary Since the stress is suppressed on the membrane part, even if the oxygen electrode boundary film part or the fuel electrode boundary film part of the polymer film is weaker than the other parts, the oxygen electrode boundary film part or the fuel Prevents damage such as strain and cracks from occurring on the extreme boundary film. It is.
  Also, an elastically deformable reinforcing member is disposed between the polymer membrane and the oxygen electrode catalyst layer or between the polymer membrane and the fuel electrode catalyst layer in a state extending inside and outside the periphery of the oxygen electrode catalyst layer or the fuel electrode catalyst layer. In such a state, when the polymer film and each layer are hot-pressed in the overlapping direction to join them, or the polymer film and each layer are pressed in the overlapping direction to bond them with an adhesive, When a pressing force is applied in the thickness direction, the reinforcing member is elastically deformed, and the stress applied to the oxygen electrode boundary membrane portion or the fuel electrode boundary membrane portion of the polymer film is released, so the stress is concentrated. Therefore, it is possible to suppress the strength of the oxygen electrode boundary film portion and the fuel electrode boundary film portion from being weakened. And, when the polymer electrolyte fuel cell is configured using the cell in which the strength of the oxygen electrode boundary film part and the fuel electrode boundary film part is suppressed from weakening, the oxygen electrode boundary film part or the fuel electrode boundary film This is more preferable in preventing the portion from being damaged.
  Accordingly, it has become possible to provide a polymer electrolyte fuel cell having excellent durability when a polymer electrolyte fuel cell is constructed.
  Further, the electrode in the polymer membrane is compared with the case where the peripheral edge of the oxygen electrode current collecting layer and the peripheral edge of the oxygen electrode catalyst layer overlap, or the case where the peripheral edge of the fuel electrode current collecting layer and the peripheral edge of the fuel electrode catalyst layer overlap. The stress applied to the boundary film portion is further reduced.
[0013]
[Invention of Claim 3]
  The characteristic structure of the cell of the polymer electrolyte fuel cell according to claim 3 is characterized in that a fibrous reinforcement is provided in a portion corresponding to a peripheral portion of the oxygen electrode catalyst layer or a peripheral portion of the fuel electrode catalyst layer in the polymer membrane. Corresponding to the peripheral part of the oxygen electrode catalyst layer or the peripheral part of the fuel electrode catalyst layer in the polymer film by mixing the material in the inner and outer direction with respect to the peripheral edge of the oxygen electrode catalyst layer or the fuel electrode catalyst layer It is configured so that the strength of the parts to be stronger than the other partsFurthermore, an oxygen electrode current collector larger than the oxygen electrode catalyst layer on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or the side opposite to the polymer film existing side in the fuel electrode catalyst layer. Or a fuel electrode current collecting layer larger than the fuel electrode catalyst layer, and a peripheral edge of the oxygen electrode catalyst layer and a peripheral edge of the oxygen electrode current collector layer, or a peripheral edge of the fuel electrode catalyst layer and the fuel electrode current collector layer The oxygen electrode current collecting layer is in contact with the oxygen electrode catalyst layer and a portion of the polymer film corresponding to the edge of the oxygen electrode catalyst layer, or the fuel electrode current collector. A layer in contact with the anode catalyst layer and a portion of the polymer membrane corresponding to the peripheral edge of the anode catalyst layer.There is in being.
  According to the characteristic configuration of the third aspect, the fibrous reinforcing material is applied to the oxygen electrode boundary film part or the fuel electrode boundary film part in the polymer film in the inner and outer directions with respect to the periphery of the oxygen electrode catalyst layer or the fuel electrode catalyst layer. Since the strength of the oxygen electrode boundary film portion or the fuel electrode boundary film portion in the polymer film is higher than that of the other parts, the oxygen electrode catalyst layer and the fuel electrode are added to the polymer film. When the catalyst layer is joined, the oxygen electrode catalyst layer and the fuel electrode catalyst layer are arranged on both sides of the polymer membrane, and even if a pressing force is applied in the overlapping direction of the polymer membrane and each layer, these oxygen It is suppressed that the intensity | strength of a pole boundary film part and a fuel electrode boundary film part becomes weak.
  And when a polymer electrolyte fuel cell is configured using such a cell, in addition to the fact that the strength of the oxygen electrode boundary film part and the fuel electrode boundary film part is suppressed in the state of the cell, Since the strength of the oxygen electrode boundary membrane part or the fuel electrode boundary film part in the polymer film is made stronger than the other parts by the fibrous reinforcing material, the pressing force is applied in the polymer film thickness direction. Even if the start / stop is repeated with pressure applied in the direction of the polymer film thickness, even if tensile stress or compressive stress is repeatedly applied to the polymer film, It is possible to prevent damage such as distortion and cracks in the fuel electrode boundary film portion.
  Accordingly, it has become possible to provide a polymer electrolyte fuel cell having excellent durability when a polymer electrolyte fuel cell is constructed.
  Also, when the periphery of the oxygen electrode current collecting layer and the portion corresponding to the peripheral portion of the oxygen electrode catalyst layer overlap, or when the periphery of the fuel electrode current collecting layer and the portion corresponding to the peripheral portion of the fuel electrode catalyst layer overlap As compared with the above, the stress applied to the electrode boundary film portion in the polymer film is further reduced.
[0014]
  [Invention of Claim 4]
  The characteristic structure of the cell of the polymer electrolyte fuel cell according to claim 4 is characterized in that the mixing rate of the fibrous reinforcing material mixed throughout the polymer film is determined by the peripheral portion of the oxygen electrode catalyst layer in the polymer film. Or the part corresponding to the peripheral part of the said oxygen electrode catalyst layer or the peripheral part of the said fuel electrode catalyst layer in the said polymer film by making the part corresponding to the peripheral part of the said fuel electrode catalyst layer higher than another part. Is configured to be stronger than other partsFurthermore, an oxygen electrode current collector larger than the oxygen electrode catalyst layer on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or the side opposite to the polymer film existing side in the fuel electrode catalyst layer. Or a fuel electrode current collecting layer larger than the fuel electrode catalyst layer, and a peripheral edge of the oxygen electrode catalyst layer and a peripheral edge of the oxygen electrode current collector layer, or a peripheral edge of the fuel electrode catalyst layer and the fuel electrode current collector layer The oxygen electrode current collecting layer is in contact with the oxygen electrode catalyst layer and a portion of the polymer film corresponding to the edge of the oxygen electrode catalyst layer, or the fuel electrode current collector. A layer in contact with the anode catalyst layer and a portion of the polymer membrane corresponding to the peripheral edge of the anode catalyst layer.There is in being.
  According to the characteristic configuration of the fourth aspect, the mixing rate of the fibrous reinforcing material mixed throughout the polymer membrane is set so that the oxygen electrode boundary membrane portion or the fuel electrode boundary membrane portion in the polymer membrane is more than the other portions. Since the strength of the oxygen electrode boundary film part or the fuel electrode boundary film part in the polymer film is made stronger than the other parts by increasing the height, the oxygen electrode catalyst layer and the fuel electrode catalyst are formed on the polymer film. Even when a pressing force is applied in the overlapping direction of the polymer membrane and each layer in a state where the oxygen electrode catalyst layer and the fuel electrode catalyst layer are arranged on both sides of the polymer membrane when the layers are joined, the oxygen electrode It is suppressed that the intensity | strength of a boundary film part and a fuel electrode boundary film part becomes weak.
  And when a polymer electrolyte fuel cell is configured using such a cell, in addition to the fact that the strength of the oxygen electrode boundary film part and the fuel electrode boundary film part is suppressed in the state of the cell, Since the strength of the oxygen electrode boundary membrane part or the fuel electrode boundary film part in the polymer film is made stronger than the other parts by the fibrous reinforcing material, the pressing force is applied in the polymer film thickness direction. Even if the start / stop is repeated with pressure applied in the direction of the polymer film thickness, even if tensile stress or compressive stress is repeatedly applied to the polymer film, It is possible to prevent damage such as distortion and cracks in the fuel electrode boundary film portion.
  Accordingly, it has become possible to provide a polymer electrolyte fuel cell having excellent durability when a polymer electrolyte fuel cell is constructed.
  Also, when the periphery of the oxygen electrode current collecting layer and the portion corresponding to the peripheral portion of the oxygen electrode catalyst layer overlap, or when the periphery of the fuel electrode current collecting layer and the portion corresponding to the peripheral portion of the fuel electrode catalyst layer overlap As compared with the above, the stress applied to the electrode boundary film portion in the polymer film is further reduced.
[0015]
[Invention of Claim 5]
A characteristic configuration of the polymer electrolyte fuel cell according to claim 5 is that a plurality of cells of the polymer electrolyte fuel cell according to any one of claims 1 to 4 form a flow path between adjacent cells. With the members positioned, they are juxtaposed in the thickness direction,
The flow path forming member is closely attached to an outer peripheral portion corresponding to a peripheral edge portion of the oxygen electrode catalyst layer in the cell adjacent to one side thereof, and forms an oxygen electrode side gas flow path between the cell and the cell, In the cell adjacent to the other side, the cell is in close contact with the outer peripheral portion corresponding to the peripheral portion of the fuel electrode catalyst layer, and the fuel electrode side gas flow path is formed between the cell and the cell. .
According to the characteristic configuration of the fifth aspect, the plurality of cells of the polymer electrolyte fuel cell according to any one of the first to fourth aspects are arranged such that the flow path forming member is positioned between the adjacent cells. In the state where the cells are juxtaposed in the thickness direction, by sandwiching from both sides of the cell juxtaposition direction so as to apply a pressing force in the cell juxtaposition direction, the connection resistance for electrically connecting each cell is reduced and the flow path is formed. The member is brought into close contact with the outer peripheral portion corresponding to the peripheral portion of the oxygen electrode catalyst layer in the cell adjacent to the one side, and closely attached to the outer peripheral portion corresponding to the peripheral portion of the fuel electrode catalyst layer in the cell adjacent to the other side. Thus, the oxygen electrode side gas flow path and the fuel electrode side gas flow path are formed in an airtight manner.
Then, the pressing force is applied in the direction of the polymer film thickness, or the start / stop is repeated with the pressing force applied in the direction of the polymer film thickness, and the tensile stress and the compressive stress are repeatedly applied to the polymer film. Even if it is applied, by using the cell according to any one of claims 1 to 4, the oxygen electrode boundary film part and the fuel electrode boundary film part of the polymer film are distorted as follows. And damage such as cracks are prevented.
That is, in the polymer electrolyte fuel cell using the cell according to claim 1, on the side opposite to the polymer membrane existence side in the oxygen electrode catalyst layer or on the side opposite to the polymer membrane existence side in the fuel electrode catalyst layer, A reinforcing member that can be elastically deformed is provided in a state that extends inside and outside the periphery of the oxygen electrode catalyst layer or the fuel electrode catalyst layer, so that a pressing force is applied in the polymer film thickness direction or the polymer film thickness direction. Even if the starting and stopping are repeated with the pressing force applied to the polymer film, even if tensile stress or compressive stress is repeatedly applied to the polymer film, the reinforcing member elastically deforms, so that the oxygen electrode boundary of the polymer film Since stress is suppressed from being applied to the membrane part and the fuel electrode boundary film part, it is possible to prevent the oxygen electrode boundary film part or the fuel electrode boundary film part from being damaged.
[0016]
3. The solid polymer fuel cell using the cell according to claim 2, wherein an oxygen electrode catalyst layer or a fuel electrode catalyst is provided between the polymer film and the oxygen electrode catalyst layer or between the polymer film and the fuel electrode catalyst layer. A state in which a pressing force is applied in the direction of the polymer film thickness or a pressing force is applied in the direction of the polymer film thickness since the elastically deformable reinforcing member is provided in the state extending from the inside to the outer periphery of the layer. Even when the polymer film is repeatedly started and stopped, and the tensile stress and compressive stress are repeatedly applied to the polymer film, the reinforcing member elastically deforms, so that the oxygen electrode boundary film part and the fuel electrode boundary film part of the polymer film Therefore, it is possible to prevent the oxygen electrode boundary film part or the fuel electrode boundary film part from being damaged.
[0017]
In the polymer electrolyte fuel cell using the cell according to claim 3, the fibrous reinforcing material is applied to the oxygen electrode catalyst layer or the fuel electrode catalyst layer on the oxygen electrode boundary film part or the fuel electrode boundary film part of the polymer film. In the polymer electrolyte fuel cell using the cell according to claim 4, the mixing rate of the fibrous reinforcing material mixed over the entire polymer film is determined by mixing the polymer reinforcing film in the inner and outer directions. By making the oxygen electrode boundary film part or the fuel electrode boundary film part in the polymer film higher than the other parts, the oxygen electrode boundary film part or the fuel electrode boundary film part in the polymer film becomes stronger than the other parts. As a result, pressing force is applied in the direction of the polymer film thickness, or starting / stopping is repeated with the pressing force applied in the direction of the polymer film thickness, and tensile or compressive stress is applied to the polymer film. Takes repeatedly Even interest, is prevented from damage to the oxygen electrode boundary membrane portion or anode boundary layer portions occurs.
Therefore, it has become possible to provide a polymer electrolyte fuel cell having excellent durability.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
First, based on FIG.1 and FIG.2, the cell C of a polymer electrolyte fuel cell is demonstrated. In FIGS. 1 and 2, the direction along the direction perpendicular to the thickness direction of the polymer film 1 in order to make the shape of each part in the direction along the thickness direction of the polymer film 1 easy to understand. The ratio of the dimension of each part in the direction along the thickness direction of the polymer film 1 with respect to the dimension of each part in FIG.
[0019]
The cell C includes an oxygen electrode catalyst layer 2c in a state where the peripheral portion is exposed on one surface of the polymer film 1 as an electrolyte layer, and the fuel electrode catalyst in a state where the peripheral portion is exposed on the other surface. A layer 3c, an oxygen electrode current collecting layer 2p on the opposite side of the oxygen electrode catalyst layer 2c from the polymer film existing side, and opposite to the polymer film existing side of the fuel electrode catalyst layer 3c. A fuel electrode current collecting layer 3p is provided on the side surface. The oxygen electrode catalyst layer 2c and the oxygen electrode current collecting layer 2p constitute the oxygen electrode 2, and the fuel electrode catalyst layer 3c and the fuel electrode current collecting layer 3p constitute the fuel electrode 3.
[0020]
In the first embodiment, the oxygen electrode side reinforcing member 4 that is elastically deformable on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer 2c and the polymer film existing side in the fuel electrode catalyst layer 3c are defined. The fuel electrode side reinforcing member 5 that is elastically deformable on the opposite side is elastically deformed by the pressing force applied in the thickness direction of the polymer membrane 1, and the peripheral portion of the oxygen electrode catalyst layer 2 c in the polymer membrane 1. The oxygen electrode catalyst layer 2c has a peripheral edge and a peripheral edge of the fuel electrode catalyst layer 3c so that the stress is prevented from concentrating on the film portion corresponding to the fuel electrode catalyst layer 3c and the peripheral edge portion of the fuel electrode catalyst layer 3c. It is provided in a state that extends both inside and outside.
[0021]
The oxygen electrode current collecting layer 2p is formed so that its planar shape is larger than that of the oxygen electrode catalyst layer 2c, and the oxygen electrode current collecting layer 2p is opposite to the polymer film existing side of the oxygen electrode catalyst layer 2c. The oxygen electrode catalyst layer 2c is provided on the side surface so as to cover the entire periphery of the oxygen electrode catalyst layer 2c and the periphery of the polymer membrane 1 is exposed over the entire periphery, and the fuel electrode current collecting layer 3p is also provided. The planar shape of the fuel electrode catalyst layer 3c is larger than that of the fuel electrode catalyst layer 3c. The peripheral portion of the layer 3c is covered over the entire periphery, and the peripheral portion of the polymer film 1 is exposed over the entire periphery.
[0022]
In other words, the polymer membrane 1 has a rectangular shape, and the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c have the same rectangular shape and are smaller than the polymer membrane 1, and the oxygen electrode current collector. The layer 2p and the fuel electrode current collecting layer 3p have the same rectangular shape and are larger than the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c. The oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c are arranged so as to be plane-symmetric with respect to the polymer film 1, and the oxygen electrode current collector layer 2p and the fuel electrode current collector layer 3p It arrange | positions so that it may become plane symmetry with respect to the molecular film 1. FIG. Therefore, a membrane portion corresponding to the peripheral portion of the oxygen electrode catalyst layer 2c in the polymer membrane 1, that is, an oxygen electrode boundary membrane portion, and a membrane portion corresponding to the peripheral portion of the fuel electrode catalyst layer 3c in the polymer membrane 1, That is, since the positions in the surface direction of the polymer film 1 in the fuel electrode boundary film portions coincide with each other, in the following description, the oxygen electrode boundary film portion in the polymer film 1 and the fuel electrode boundary film portion in the polymer film 1 respectively. May be referred to as an electrode boundary film portion 1W in the polymer film 1.
[0023]
The oxygen electrode side reinforcing member 4 and the fuel electrode side reinforcing member 5 have the same rectangular frame shape, the outer periphery has the same rectangular shape as the polymer film 1, and the inner periphery has the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer. The thickness is a rectangular shape smaller than 3c, and the thickness is the sum of the thicknesses of the oxygen electrode catalyst layer 2c and the oxygen electrode current collector layer 2p (that is, the fuel electrode catalyst layer 3c and the fuel electrode current collector layer 3p, respectively). (Thickness plus thickness) is thinner.
[0024]
Then, in a state where the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c are distributed and arranged on both surfaces of the polymer film 1, the polymer film 1 and each layer are hot-pressed in the overlapping direction to join them, After forming the membrane assembly, the oxygen electrode side reinforcing member 4 and the oxygen electrode current collecting layer 2p are arranged in the order of description from the polymer membrane 1 side on the oxygen electrode catalyst layer 2c side of the electrode-membrane assembly. At the same time, a rectangular frame-shaped oxygen electrode side sealing material 6 is superimposed on the exposed portion of the oxygen electrode side reinforcing member 4 in the rectangular frame shape, and the fuel electrode side reinforcement is provided on the fuel electrode catalyst layer 3c side of the electrode-membrane assembly. The member 5 and the fuel electrode current collecting layer 3p are arranged and stacked in the order of description from the polymer film 1 side, and the rectangular frame-shaped fuel electrode side sealing material 7 is stacked on the exposed portion of the rectangular frame shape in the fuel electrode side reinforcing member 5. The cell C is configured.
[0025]
The oxygen electrode side sealing material 6 and the fuel electrode side sealing material 7 have the same rectangular frame shape, the outer periphery is the same rectangular shape as the polymer film 1, and the inner periphery is the oxygen electrode current collecting layer 2p and the fuel electrode collection. It is the same rectangular shape as the outer periphery of the electric layer 3p.
[0026]
1 shows a state in which a pressing force is applied in the thickness direction of the polymer film 1 to the cell C configured as described above, that is, a state in which the cell C is incorporated in a cell stack NC described later. It shows a state in which each member is deformed in the overlapping portion between the members due to the pressing force. However, the shape in which each member is deformed by the pressing force is not limited to the shape shown in FIG.
[0027]
The polymer membrane 1 is formed of a fluororesin ion exchange membrane (for example, Nafion 112) having proton conductivity, and has a thickness of, for example, 50 μm.
The oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c have the same configuration, are formed of a porous conductive material made of carbon, and carry an electrode catalyst made of platinum and a platinum-based alloy, respectively. The thickness is, for example, about 20 μm.
The oxygen electrode current collecting layer 2p and the fuel electrode current collecting layer 3p have the same configuration as each other, and are formed of a porous conductive material such as carbon paper or carbon felt, and a water repellent (PTFE: polytetrafluoroethylene). Etc.) and has a thickness of, for example, about 350 μm.
Further, the oxygen electrode side reinforcing member 4 and the fuel electrode side reinforcing member 5 have the same configuration, and are made of an elastically deformable and airtight material, for example, the same material as that for forming the polymer film 1. The thickness is about the same as that of the polymer film 1, for example.
The oxygen electrode side sealing material 6 and the fuel electrode side sealing material 7 have the same configuration as each other, and are formed of an airtight material such as a PTFE sheet, and the thickness thereof is, for example, about 250 μm.
[0028]
Next, a polymer electrolyte fuel cell configured using a plurality of the cells C will be described with reference to FIGS. 3 and 13 to 16. 3 and FIGS. 13 to 6, as in FIGS. 1 and 2, the polymer film 1 with respect to the dimensions of the respective parts in the direction along the direction orthogonal to the thickness direction of the polymer film 1. The ratio of the dimension of each part in the direction along the thickness direction is made larger than actual.
The polymer electrolyte fuel cell includes a cell stack NC. As shown in FIG. 16, the cell stack NC has a plurality of cells C in a state where the oxygen electrode side separator 8 and the fuel electrode side separator 9 as flow path forming members are positioned between adjacent cells. In addition, the pressing force is applied in the cell juxtaposition direction in a state where the power collecting current collector 10 and each fluid supply / discharge end plate 11 are arranged at both ends in the stacking direction. And it is comprised by pinching with the clamping member (illustration omitted) from the both sides of a cell juxtaposition direction.
[0029]
The oxygen electrode side separator 8 is in close contact with the outer peripheral portion corresponding to the peripheral portion of the oxygen electrode catalyst layer 2c in the cell C adjacent thereto, and is configured to form an oxygen electrode side gas flow path s between the cell C and the oxygen electrode side separator 8. The fuel electrode side separator 9 is in close contact with the outer peripheral portion corresponding to the peripheral portion of the fuel electrode catalyst layer 3c in the cell C adjacent thereto, so as to form the fuel electrode side gas flow path f between the cells C. It is configured.
[0030]
The oxygen electrode side separator 8 and the fuel electrode side separator 9 are formed of a conductive material made of carbon and having a dense airtightness.
[0031]
As shown in FIG. 3 and FIGS. 13 to 15, the oxygen electrode side separator 8 forms an oxygen electrode side gas flow path s through which the oxygen electrode side reaction gas flows on the surface on the oxygen electrode 2 side. An oxygen electrode side gas flow groove is formed, and a cooling water flow groove that forms the cooling water flow path w is formed on the opposite surface.
The fuel electrode side separator 9 is formed on the surface on the fuel electrode 3 side with a fuel electrode side gas flow groove for forming a fuel electrode side gas flow channel f through which the fuel electrode side reaction gas flows, and on the opposite surface. Further, a cooling water flow groove for forming a cooling water flow path that is plane-symmetric with the cooling water flow groove of the oxygen electrode side separator 8 is formed.
[0032]
Further, each of the cell C, the oxygen electrode side separator 8 and the fuel electrode side separator 9 has six holes Ch, 8h, penetrating in the thickness direction in a state where each cell C, the oxygen electrode side separator 8 and the fuel electrode side separator 9 are stacked in the stacking direction. 9h is formed. When viewed in the stacking direction, two of the six holes Ch, 8h, 9h formed in the cell C, the oxygen electrode side separator 8 and the fuel electrode side separator 9 are the flow paths of the oxygen electrode side gas flow path s. The other two overlap each other at both ends of the flow path of the fuel electrode side gas flow path f, and the other two overlap at both ends of the flow path of the cooling water flow path w. It overlaps separately.
[0033]
Accordingly, in the cell stack NC, six passages are formed in which the holes Ch, 8h, 9h of the cell C, the oxygen electrode side separator 8 and the fuel electrode side separator 9 are formed in the stacking direction. Two of them communicate with the both ends of the flow path of each oxygen electrode side gas flow path s separately, and the other two communicate with the both ends of the flow path of each fuel electrode side gas flow path f. The other two communicate with each other separately at both ends of the flow path of each cooling water flow path w.
Note that two passages respectively communicating with both ends of the flow path of each oxygen electrode side gas flow path s are respectively connected to the oxygen electrode side communication path Ts and both ends of the flow path of each fuel electrode side gas flow path f. The two passages communicating with the respective parts are referred to as fuel electrode side communication passages Tf, and the two passages communicating with the both ends of the flow passages of the respective cooling water passages w are referred to as cooling water side communication passages Tw, respectively. .
[0034]
Further, as shown in FIG. 16, end plates 11 are provided at both ends in the stacking direction of the cell stack NC. One end plate 11 is connected to one end portion of the two oxygen electrode side communication passages Ts, one of the oxygen electrode side gas connection portions 12s connected to one end portion, and one of the two fuel electrode side communication passages Tf. The fuel electrode side gas connection portion 12f that is in communication with the other end portion and the cooling water connection portion 12w that is in communication with one end portion of the two cooling water communication passages Tw are provided. Further, the other end plate 11 is connected to the other end of the two oxygen electrode side communication passages Ts and is connected to the other end portion of the oxygen electrode side gas connection portion 12s and of the two fuel electrode side communication passages Tf. The fuel electrode side gas connection portion 12f communicating with the other end of the cooling water and the cooling water connection portion 12w communicating with the other end of the two cooling water communication passages Tw are provided.
[0035]
Of the two oxygen electrode side gas connection portions 12s, one is used for supplying the oxygen electrode side reaction gas, and the other is used for discharging the oxygen electrode side reaction gas. One of the connection portions 12f is used for supplying the fuel electrode side reaction gas, the other is used for discharging the fuel electrode side reaction gas, and one of the two cooling water connection portions 12w is used. The other is used for supplying cooling water, and the other is used for discharging cooling water.
[0036]
The hydrogen-containing gas obtained by reforming the hydrocarbon-based raw fuel is humidified by a humidifier (not shown) as a fuel electrode side reaction gas, and then the cell stack is connected from the oxygen electrode side gas connection portion 12s for supply. After supplying air to the NC and humidifying the air from the blower (not shown) as oxygen electrode side reaction gas in a humidifier (not shown), the cell stack is connected from the fuel electrode side gas connection portion 12f for supply. Supply to NC.
In addition, a cooling water pump (not shown) supplies the cooling water to the cell stack NC from the supplying cooling water connecting portion 12w.
[0037]
Then, the humidified oxygen electrode side reaction gas is supplied from one oxygen electrode side communication path Ts to the oxygen electrode side gas flow path s of each cell C as shown by solid line arrows in FIGS. 14 and 15. After flowing through the oxygen electrode side gas flow path s, it flows out to the other oxygen electrode side communication channel Ts, flows through the oxygen electrode side communication channel Ts, and is discharged from the discharge oxygen electrode side gas connection portion 12s. The
The fuel electrode side reaction gas is supplied from one fuel electrode side communication path Tf to the fuel electrode side gas flow path f of each cell C as shown by a two-dot chain arrow in FIGS. After flowing through the electrode side gas flow path f, it flows out to the other fuel electrode side communication passage Tf, flows through the fuel electrode side communication passage Tf, and is discharged from the discharge fuel electrode side gas connecting portion 12f. .
Further, as shown by a one-dot chain line arrow in FIG. 14 and FIG. 15, the cooling water is supplied from one cooling water communication path Tw to the cooling water flow path w of each cell C and flows through the cooling water flow path w. Then, it flows out to the other cooling water communication passage Tw, flows through the cooling water communication passage Tw, and is discharged from the cooling water connection portion 12w.
[0038]
In each cell C, oxygen in the oxygen electrode side reaction gas is obtained in a state where the polymer film 1 is moistened by water vapor contained in each of the oxygen electrode side reaction gas and the fuel electrode side reaction gas. Is generated by an electrochemical reaction between hydrogen and hydrogen in the fuel electrode side reaction gas. Further, the temperature of each cell C is maintained at a predetermined temperature by the flow of the cooling water.
[0039]
In the cell stack NC configured as described above, a pressing force is applied in the cell juxtaposition direction, so that the electrode boundary film portion 1W in the polymer film 1 has an oxygen electrode catalyst layer 2c, an oxygen electrode current collector. The edge of each of the layer 2p, the oxygen electrode side sealing material 6, the fuel electrode catalyst layer 3c, the fuel electrode current collecting layer 3p, and the fuel electrode side sealing material 7 is more easily stressed than the other parts, but the oxygen electrode side reinforcement The elastic deformation of the member 4 and the fuel electrode side reinforcing member 5 suppresses stress from being applied to the electrode boundary film portion 1W of the polymer film 1, and the polymer film 1 is repeatedly started and stopped. Even when tensile stress or compressive stress is repeatedly applied to the electrode film, the oxygen electrode side reinforcing member 4 and the fuel electrode side reinforcing member 5 are elastically deformed, so that stress is applied to the electrode boundary film portion 1W of the polymer film 1. High because it is suppressed The creep rupture occurs can be prevented in the electrode boundary membrane portion 1W of the child layer 1.
Moreover, the oxygen electrode current collecting layer 2p is made larger than the oxygen electrode catalyst layer 2c, the periphery of the oxygen electrode current collector layer 2p is shifted from the periphery of the oxygen electrode catalyst layer 2c, and the fuel electrode current collector layer 3p is made fuel. Since the periphery of the fuel electrode current collecting layer 3p is shifted from the periphery of the fuel electrode catalyst layer 3c so as to be larger than the electrode catalyst layer 3c, the periphery of the oxygen electrode current collector layer 2p and the periphery of the oxygen electrode catalyst layer 2c And the stress applied to the electrode boundary film portion 1W in the polymer film 1 is further reduced as compared with the case where the periphery of the fuel electrode current collecting layer 3p and the periphery of the fuel electrode catalyst layer 3c overlap. It is configured.
[0040]
Hereinafter, the results of comparing the durability of the cell C according to the present invention configured as described above and the conventional cell C shown in FIGS. 18 and 19 will be described. For comparison of durability, the oxygen electrode side separator 5 is attached to the oxygen electrode 2 side, and the fuel electrode side separator 6 is attached to the fuel electrode 3 side, and tightened from both sides so that the output voltage becomes the highest. A single cell was used. In both cells C, the area of the polymer membrane 1 is 75 mm × 75 mm, and the areas of the oxygen electrode 2 and the fuel electrode 3 are 50 mm × 50 mm.
[0041]
For each of the cell of the present invention and the conventional cell, with the gas outlets of the oxygen electrode side gas flow path s and the fuel electrode side gas flow path f opened to the atmosphere, air is used as the oxygen electrode side reaction gas to the humidifier. After being humidified, it is supplied to the oxygen electrode side gas flow path s, and pure hydrogen gas is humidified by the humidifier as the fuel electrode side reaction gas, and then supplied to the fuel electrode side gas flow path f to provide an electronic load. Using the device, the current density is 3000 A / m2The power was generated at a constant current so that the output voltage was measured, and the output voltage was measured and compared.
The cell temperature was maintained at 70 ° C., the fuel utilization rate was set to 60%, and the air utilization rate was set to 40%.
[0042]
FIG. 17 shows changes in output voltage over time for each of the cell of the present invention and the conventional cell.
Until 3500 hours elapse from the start of power generation, the output voltage of the cell of the present invention and the conventional cell decreases at substantially the same reduction rate. It can be seen that the rate of voltage decrease suddenly increases, the output voltage becomes unstable, and the performance of the conventional cell is greatly reduced compared to the cell of the present invention.
[0043]
The open circuit voltage at the start of power generation is 900 mV or higher for both the cell of the present invention and the conventional cell, and the open circuit voltage after the generation time of 5000 hours is 900 mV or higher for the cell of the present invention. The cell had dropped to 850 mV.
After the generation time of 5000 hours, the cell was disassembled and the polymer film 1 was observed. In the conventional cell, a crack occurred in the electrode boundary film portion 1W. It is probable that the output voltage decreased due to the occurrence of On the other hand, in the cell of the present invention, there was no abnormality in the polymer film 1.
[0044]
[Second Embodiment]
First, based on FIG.4 and FIG.5, the cell C of a polymer electrolyte fuel cell is demonstrated. 4 and 5, as in FIGS. 1 and 2, in the thickness direction of the polymer film 1 with respect to the dimensions of each part in the direction along the direction orthogonal to the thickness direction of the polymer film 1. The ratio of the dimensions of each part in the direction along the direction is made larger than the actual ratio.
[0045]
The cell C includes an oxygen electrode catalyst layer 2c in a state where the peripheral portion is exposed on one surface of the polymer film 1 as an electrolyte layer, and the fuel electrode catalyst in a state where the peripheral portion is exposed on the other surface. A layer 3c, an oxygen electrode current collecting layer 2p on the opposite side of the oxygen electrode catalyst layer 2c from the polymer film existing side, and opposite to the polymer film existing side of the fuel electrode catalyst layer 3c. A fuel electrode current collecting layer 3p is provided on the side surface. The oxygen electrode catalyst layer 2c and the oxygen electrode current collecting layer 2p constitute the oxygen electrode 2, and the fuel electrode catalyst layer 3c and the fuel electrode current collecting layer 3p constitute the fuel electrode 3.
[0046]
In the second embodiment, the elastically deformable oxygen electrode side reinforcing member 1s is provided between the polymer membrane 1 and the oxygen electrode catalyst layer 2c, and the elastic material is provided between the polymer membrane 1 and the fuel electrode catalyst layer 3c. The deformable fuel electrode side reinforcing member 1 f is elastically deformed by the pressing force applied in the thickness direction of the polymer film 1, and the peripheral portion of the oxygen electrode catalyst layer 2 c and the fuel electrode catalyst in the polymer film 1. In order to suppress the concentration of stress on the film portion corresponding to the peripheral portion of the layer 3c, the oxygen electrode catalyst layer 2c is provided in a state extending inside and outside the periphery of the oxygen electrode catalyst layer 2c and in a state extending inside and outside the periphery of the fuel electrode catalyst layer 3c.
[0047]
In other words, the polymer film 1 has a rectangular shape, and on the surface of the polymer film 1 on the oxygen electrode catalyst layer 2c side, a rectangular frame-shaped film portion corresponding to the peripheral edge of the oxygen electrode catalyst layer 2c is projected. Thus, the projecting portion functions as the oxygen electrode side reinforcing member 1s, and on the surface of the polymer film 1 on the fuel electrode catalyst layer 3c side, a rectangular frame-shaped film corresponding to the peripheral portion of the fuel electrode catalyst layer 3c. A portion is protruded, and the protrusion is configured to function as the fuel electrode side reinforcing member 1f. That is, the oxygen electrode side reinforcing member 1 s and the fuel electrode side reinforcing member 1 f are formed integrally with the polymer film 1. Note that the widths of the oxygen electrode side reinforcing member 1s and the fuel electrode side reinforcing member 1f are such that the oxygen electrode side is closer to the oxygen electrode than the positions corresponding to the peripheral edges of the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c. The width extends beyond the position corresponding to the periphery of the current collecting layer 2p and the anode current collecting layer 3p.
[0048]
Shapes and sizes of the polymer membrane 1, the oxygen electrode catalyst layer 2c, the fuel electrode catalyst layer 3c, the oxygen electrode current collecting layer 2p, the fuel electrode current collecting layer 3p, the oxygen electrode side sealing material 6 and the fuel electrode side sealing material 7 Since this is the same as in the first embodiment, a description thereof will be omitted. That is, also in the second embodiment, as in the first embodiment, in the following description, the oxygen electrode boundary film part in the polymer film 1 and the fuel electrode boundary film part in the polymer film 1 are both in the polymer film 1. Sometimes referred to as an electrode boundary film portion 1W.
[0049]
Then, in a state where the oxygen electrode catalyst layer 2c is arranged on one side of the polymer film 1 and the fuel electrode catalyst layer 3c is arranged on the other side, the polymer film 1 and each layer are hot-pressed in the overlapping direction. Are joined together to form an electrode-membrane assembly, and then the oxygen electrode current collecting layer 2p is superimposed on the oxygen electrode catalyst layer 2c side of the electrode-membrane assembly, and a rectangular frame-shaped polymer membrane on that side 1, an oxygen electrode side sealing material 6 having a rectangular frame shape is stacked on the exposed portion of 1, and a fuel electrode current collecting layer 3 p is stacked on the fuel electrode catalyst layer 3 c side of the electrode-membrane assembly. A cell C is configured by arranging a fuel electrode side sealing material 7 having a rectangular frame shape so as to overlap an exposed portion of the polymer film 1.
[0050]
4 shows a state in which a pressing force is applied to the cell C configured as described above in the thickness direction of the polymer film 1, that is, a state in which the cell C is incorporated in a cell stack NC described later. It shows a state in which each member is deformed in the overlapping portion between the members due to the pressing force. However, the shape in which each member is deformed by the pressing force is not limited to the shape shown in FIG.
[0051]
As described above, when an electrode-membrane assembly is manufactured by hot pressing while applying a pressing force in the thickness direction of the polymer membrane 1, the edge of the oxygen electrode catalyst layer 2c or the edge of the fuel electrode catalyst layer 3c is used. Since stress concentration on the electrode boundary film portion 1W in the polymer film 1 can be suppressed by elastic deformation of the oxygen electrode side reinforcing member 1s and the fuel electrode side reinforcing member 1f, the electrode in the polymer film 1 It can suppress that the intensity | strength of the boundary film part 1W becomes weak.
[0052]
The materials and thicknesses of the polymer film 1, the oxygen electrode catalyst layer 2c, the fuel electrode catalyst layer 3c, the oxygen electrode current collecting layer 2p, and the fuel electrode current collecting layer 3p are the same as those in the first embodiment. Further, the thickness of the oxygen electrode side reinforcing member 1s and the thickness of the fuel electrode side reinforcing member 1f are the same as the thickness of the oxygen electrode side reinforcing member 4 and the thickness of the fuel electrode side reinforcing member 5 of the first embodiment, respectively. is there.
[0053]
FIG. 6 shows a longitudinal sectional view of a main part of a polymer electrolyte fuel cell configured by using a plurality of the cells C described above. The stacked structure of the cell stack NC constituting the polymer electrolyte fuel cell, that is, a plurality of the cells C are provided with an oxygen electrode side separator 8 and a fuel electrode side separator 9 as flow path forming members between adjacent cells. In the state of being placed, juxtaposed in the thickness direction, and further, in the state in which the current collecting part 10 for power extraction and the end plates 11 for supplying and discharging each fluid are arranged at both ends in the stacking direction, The structure of sandwiching by the sandwiching members (not shown) from both sides in the cell juxtaposition direction so as to apply the pressing force is the same as the structure described with reference to FIGS. 13 to 16 in the first embodiment. Is omitted. Also in FIG. 6, as in FIGS. 1 and 2, in the direction along the thickness direction of the polymer film 1 with respect to the dimension of each part in the direction along the direction orthogonal to the thickness direction of the polymer film 1. The ratio of the dimensions of each part is made larger than the actual ratio.
[0054]
In the cell stack NC configured as described above, a pressing force is applied in the cell juxtaposition direction, so that the electrode boundary film portion 1W in the polymer film 1 has an oxygen electrode catalyst layer 2c, an oxygen electrode current collector. The edge of each of the layer 2p, the oxygen electrode side sealing material 6, the fuel electrode catalyst layer 3c, the fuel electrode current collecting layer 3p, and the fuel electrode side sealing material 7 is more easily stressed than the other parts, but the oxygen electrode side reinforcement The elastic deformation of the member 1s and the fuel electrode side reinforcing member 1f suppresses the application of stress to the electrode boundary film portion 1W of the polymer film 1, and the polymer film 1 is repeatedly started and stopped. Even when tensile stress or compressive stress is repeatedly applied to the electrode film, the oxygen electrode side reinforcing member 1s and the fuel electrode side reinforcing member 1f are elastically deformed to apply stress to the electrode boundary film portion 1W of the polymer film 1. Be suppressed In, the creep rupture occurs in the electrode boundary membrane portion 1W of the polymer film 1 is prevented.
Moreover, the oxygen electrode current collecting layer 2p is made larger than the oxygen electrode catalyst layer 2c, the periphery of the oxygen electrode current collector layer 2p is shifted from the periphery of the oxygen electrode catalyst layer 2c, and the fuel electrode current collector layer 3p is made fuel. Since the periphery of the fuel electrode current collecting layer 3p is shifted from the periphery of the fuel electrode catalyst layer 3c so as to be larger than the electrode catalyst layer 3c, the periphery of the oxygen electrode current collector layer 2p and the periphery of the oxygen electrode catalyst layer 2c And the stress applied to the electrode boundary film portion 1W in the polymer film 1 is further reduced as compared with the case where the periphery of the fuel electrode current collecting layer 3p and the periphery of the fuel electrode catalyst layer 3c overlap. It is configured.
[0055]
[Third Embodiment]
First, based on FIG.7 and FIG.8, the cell C of a polymer electrolyte fuel cell is demonstrated. 7 and 8, as in FIGS. 1 and 2, in the thickness direction of the polymer film 1 with respect to the dimensions of each part in the direction along the direction orthogonal to the thickness direction of the polymer film 1. The ratio of the dimensions of each part in the direction along the direction is made larger than the actual ratio.
[0056]
The cell C includes an oxygen electrode catalyst layer 2c in a state where the peripheral portion is exposed on one surface of the polymer film 1 as an electrolyte layer, and the fuel electrode catalyst in a state where the peripheral portion is exposed on the other surface. A layer 3c, an oxygen electrode current collecting layer 2p on the opposite side of the oxygen electrode catalyst layer 2c from the polymer film existing side, and opposite to the polymer film existing side of the fuel electrode catalyst layer 3c. A fuel electrode current collecting layer 3p is provided on the side surface. The oxygen electrode catalyst layer 2c and the oxygen electrode current collecting layer 2p constitute the oxygen electrode 2, and the fuel electrode catalyst layer 3c and the fuel electrode current collecting layer 3p constitute the fuel electrode 3.
[0057]
In the third embodiment, the fibrous reinforcing material 1r is attached to the oxygen electrode catalyst layer 1c and the fuel electrode catalyst at portions corresponding to the periphery of the oxygen electrode catalyst layer 2c and the periphery of the fuel electrode catalyst layer 3c in the polymer membrane 1. By mixing in the inner and outer directions with respect to the periphery of the layer 3c, the strength of the peripheral portion of the oxygen electrode catalyst layer 2c or the peripheral portion of the fuel electrode catalyst layer 3c in the polymer membrane 1 is stronger than the other portions. It is comprised so that it may become.
[0058]
Shapes and sizes of the polymer membrane 1, the oxygen electrode catalyst layer 2c, the fuel electrode catalyst layer 3c, the oxygen electrode current collecting layer 2p, the fuel electrode current collecting layer 3p, the oxygen electrode side sealing material 6 and the fuel electrode side sealing material 7 Since this is the same as in the first embodiment, a description thereof will be omitted. That is, also in the third embodiment, as in the first embodiment, in the following description, the oxygen electrode boundary film part in the polymer film 1 and the fuel electrode boundary film part in the polymer film 1 are both in the polymer film 1. Sometimes referred to as an electrode boundary film portion 1W.
[0059]
And in 3rd Embodiment, the electrode boundary-film part 1W in the polymer film 1 is made from others by mixing the fibrous reinforcement 1r in the rectangular-frame-shaped electrode boundary film part 1W in the polymer film 1. Are also reinforced (so-called fibril reinforcement) to increase the strength. The range in which the fibrous reinforcing material 1r is mixed in the polymer film 1 is from the inside corresponding to the peripheral edges of the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c from the inside, and the oxygen electrode current collecting layer 2p and the fuel electrode. The range extends outward from the position corresponding to the peripheral edge of the current collecting layer 3p.
[0060]
Then, in a state where the oxygen electrode catalyst layer 2c is arranged on one side of the polymer film 1 and the fuel electrode catalyst layer 3c is arranged on the other side, the polymer film 1 and each layer are hot-pressed in the overlapping direction. Are joined together to form an electrode-membrane assembly, and then the oxygen electrode current collecting layer 2p is superimposed on the oxygen electrode catalyst layer 2c side of the electrode-membrane assembly, and a rectangular frame-shaped polymer membrane on that side 1, an oxygen electrode side sealing material 6 having a rectangular frame shape is stacked on the exposed portion of 1, and a fuel electrode current collecting layer 3 p is stacked on the fuel electrode catalyst layer 3 c side of the electrode-membrane assembly. A cell C is configured by arranging a fuel electrode side sealing material 7 having a rectangular frame shape so as to overlap an exposed portion of the polymer film 1.
[0061]
7 shows a state in which a pressing force is applied to the cell C configured as described above in the thickness direction of the polymer film 1, that is, a state in which the cell C is incorporated in a cell stack NC described later. It shows a state in which each member is deformed in the overlapping portion between the members due to the pressing force. However, the shape in which each member is deformed by the pressing force is not limited to the shape shown in FIG.
[0062]
As described above, when an electrode-membrane assembly is manufactured by hot pressing while applying a pressing force in the thickness direction of the polymer membrane 1, the edge of the oxygen electrode catalyst layer 2c or the edge of the fuel electrode catalyst layer 3c increases. Even if stress concentrates on the electrode boundary film portion 1W in the molecular film 1, the strength of the electrode boundary film portion 1W can be increased by mixing the fibrous reinforcing material 1r into the electrode boundary film portion 1W in the polymer film 1. Since it is made stronger than the part, it can suppress that the intensity | strength of the electrode boundary film part 1W in the polymer film 1 becomes weak.
[0063]
The materials and thicknesses of the polymer film 1, the oxygen electrode catalyst layer 2c, the fuel electrode catalyst layer 3c, the oxygen electrode current collecting layer 2p, and the fuel electrode current collecting layer 3p are the same as those in the first embodiment.
As the fibrous reinforcing material, various fibrous materials that do not adversely affect the polymer membrane 1 and are stable under the operating conditions of the solid polymer fuel cell can be used, but the reinforcing action is further increased. Is preferably a fibrous material having elasticity, for example, PTFE fibrils (microfibers) can be used.
[0064]
FIG. 9 shows a longitudinal sectional view of a main part of a polymer electrolyte fuel cell configured by using a plurality of the cells C described above. Note that the stack structure of the cell stack NC constituting the polymer electrolyte fuel cell is the same as the structure described with reference to FIGS. 13 to 16 in the first embodiment, and thus the description thereof is omitted. Also in FIG. 9, as in FIGS. 1 and 2, in the direction along the thickness direction of the polymer film 1 with respect to the dimension of each part in the direction along the direction orthogonal to the thickness direction of the polymer film 1. The ratio of the dimensions of each part is made larger than the actual ratio.
[0065]
In the cell stack NC configured as described above, a pressing force is applied in the cell juxtaposition direction, so that the electrode boundary film portion 1W in the polymer film 1 has an oxygen electrode catalyst layer 2c, an oxygen electrode current collector. The edge of each of the layer 2p, the oxygen electrode side sealing material 6, the fuel electrode catalyst layer 3c, the fuel electrode current collecting layer 3p, and the fuel electrode side sealing material 7 is applied with a larger stress than the other parts, The polymer film 1 is repeatedly started and stopped, and tensile stress and compressive stress are repeatedly applied. However, the electrode boundary film portion 1W in the polymer film 1 is reinforced in a fibrous manner so as to be stronger than other portions. Since it is reinforced by the material 1r, creep failure is prevented from occurring in the electrode boundary film portion 1W.
Moreover, the oxygen electrode current collecting layer 2p is made larger than the oxygen electrode catalyst layer 2c, the periphery of the oxygen electrode current collector layer 2p is shifted from the periphery of the oxygen electrode catalyst layer 2c, and the fuel electrode current collector layer 3p is made fuel. Since the periphery of the fuel electrode current collecting layer 3p is shifted from the periphery of the fuel electrode catalyst layer 3c so as to be larger than the electrode catalyst layer 3c, the periphery of the oxygen electrode current collector layer 2p and the periphery of the oxygen electrode catalyst layer 2c And the stress applied to the electrode boundary film portion 1W in the polymer film 1 is further reduced as compared with the case where the periphery of the fuel electrode current collecting layer 3p and the periphery of the fuel electrode catalyst layer 3c overlap. It is configured.
[0066]
[Fourth Embodiment]
First, based on FIG.10 and FIG.11, the cell C of a polymer electrolyte fuel cell is demonstrated. 10 and 11, as in FIGS. 1 and 2, in the thickness direction of the polymer film 1 with respect to the dimension of each part in the direction along the direction orthogonal to the thickness direction of the polymer film 1. The ratio of the dimensions of each part in the direction along the direction is made larger than the actual ratio.
[0067]
The cell C includes an oxygen electrode catalyst layer 2c in a state where the peripheral portion is exposed on one surface of the polymer film 1 as an electrolyte layer, and the fuel electrode catalyst in a state where the peripheral portion is exposed on the other surface. A layer 3c, an oxygen electrode current collecting layer 2p on the opposite side of the oxygen electrode catalyst layer 2c from the polymer film existing side, and opposite to the polymer film existing side of the fuel electrode catalyst layer 3c. A fuel electrode current collecting layer 3p is provided on the side surface. The oxygen electrode catalyst layer 2c and the oxygen electrode current collecting layer 2p constitute the oxygen electrode 2, and the fuel electrode catalyst layer 3c and the fuel electrode current collecting layer 3p constitute the fuel electrode 3.
[0068]
In the third embodiment, the mixing rate of the fibrous reinforcing material 1r mixed throughout the polymer membrane 1 corresponds to the peripheral portion of the oxygen electrode catalyst layer 2c and the peripheral portion of the fuel electrode catalyst layer 3c in the polymer membrane 1. By making the portion to be higher than the other portions, the strength of the portion corresponding to the peripheral portion of the oxygen electrode catalyst layer 2c and the peripheral portion of the fuel electrode catalyst layer 3c in the polymer membrane 1 is made stronger than the other portions. It is configured. In the polymer film 1, the range in which the mixing rate of the fibrous reinforcing material 1r is higher than that of other portions is greater than the position corresponding to the periphery of the oxygen electrode catalyst layer 2c and the fuel electrode catalyst layer 3c from the inside. This is a range extending outward from the positions corresponding to the peripheral edges of the electrode current collecting layer 2p and the fuel electrode current collecting layer 3p.
[0069]
Shapes and sizes of the polymer membrane 1, the oxygen electrode catalyst layer 2c, the fuel electrode catalyst layer 3c, the oxygen electrode current collecting layer 2p, the fuel electrode current collecting layer 3p, the oxygen electrode side sealing material 6 and the fuel electrode side sealing material 7 Since this is the same as in the first embodiment, a description thereof will be omitted. That is, also in the fourth embodiment, as in the first embodiment, in the following description, the oxygen electrode boundary film part in the polymer film 1 and the fuel electrode boundary film part in the polymer film 1 are both in the polymer film 1. Sometimes referred to as an electrode boundary film portion 1W.
[0070]
In the fourth embodiment, the fibrous reinforcing material 1r is mixed into the entire polymer film 1 to reinforce the polymer film 1 (so-called fibril reinforcement). By increasing the mixing rate of the rectangular frame-shaped electrode boundary film portion 1W in the polymer film 1 higher than the other portions, the electrode boundary film portion 1W in the polymer film 1 is made stronger than the others. It is.
[0071]
Then, in a state where the oxygen electrode catalyst layer 2c is arranged on one side of the polymer film 1 and the fuel electrode catalyst layer 3c is arranged on the other side, the polymer film 1 and each layer are hot-pressed in the overlapping direction. Are joined together to form an electrode-membrane assembly, and then the oxygen electrode current collecting layer 2p is superimposed on the oxygen electrode catalyst layer 2c side of the electrode-membrane assembly, and a rectangular frame-shaped polymer membrane on that side 1, an oxygen electrode side sealing material 6 having a rectangular frame shape is stacked on the exposed portion of 1, and a fuel electrode current collecting layer 3 p is stacked on the fuel electrode catalyst layer 3 c side of the electrode-membrane assembly. A cell C is configured by arranging a fuel electrode side sealing material 7 having a rectangular frame shape so as to overlap an exposed portion of the polymer film 1.
[0072]
10 shows a state in which a pressing force is applied to the cell C configured as described above in the thickness direction of the polymer film 1, that is, a state in which the cell C is incorporated in a cell stack NC described later. It shows a state in which each member is deformed in the overlapping portion between the members due to the pressing force. However, the shape in which each member is deformed by the pressing force is not limited to the shape shown in FIG.
[0073]
As described above, when an electrode-membrane assembly is manufactured by hot pressing while applying a pressing force in the thickness direction of the polymer membrane 1, the edge of the oxygen electrode catalyst layer 2c or the edge of the fuel electrode catalyst layer 3c increases. Even if stress concentrates on the electrode boundary film part 1W in the molecular film 1, the mixing ratio of the fibrous reinforcing material 1r in the electrode boundary film part 1W in the polymer film 1 is made higher than that in other parts, whereby the electrode boundary film Since the strength of the portion 1W is stronger than the other portions, it is possible to suppress the strength of the electrode boundary film portion 1W in the polymer film 1 from being weakened.
[0074]
The materials and thicknesses of the polymer film 1, the oxygen electrode catalyst layer 2c, the fuel electrode catalyst layer 3c, the oxygen electrode current collecting layer 2p, and the fuel electrode current collecting layer 3p are the same as those in the first embodiment.
As the fibrous reinforcing material, the same material as described in the third embodiment can be used.
[0075]
FIG. 12 shows a longitudinal sectional view of a main part of a polymer electrolyte fuel cell configured by using a plurality of the cells C described above. Note that the stack structure of the cell stack NC constituting the polymer electrolyte fuel cell is the same as the structure described with reference to FIGS. 13 to 16 in the first embodiment, and thus the description thereof is omitted. Also in FIG. 12, as in FIGS. 1 and 2, in the direction along the thickness direction of the polymer film 1 with respect to the dimension of each part in the direction along the direction perpendicular to the thickness direction of the polymer film 1. The ratio of the dimensions of each part is made larger than the actual ratio.
[0076]
In the cell stack NC configured as described above, a pressing force is applied in the cell juxtaposition direction, so that the electrode boundary film portion 1W in the polymer film 1 has an oxygen electrode catalyst layer 2c, an oxygen electrode current collector. The edge of each of the layer 2p, the oxygen electrode side sealing material 6, the fuel electrode catalyst layer 3c, the fuel electrode current collecting layer 3p, and the fuel electrode side sealing material 7 is applied with a larger stress than the other parts, The polymer film 1 is repeatedly started and stopped, and tensile stress and compressive stress are repeatedly applied. However, the electrode boundary film portion 1W in the polymer film 1 is reinforced in a fibrous manner so as to be stronger than other portions. Since it is reinforced by the material 1r, creep failure is prevented from occurring in the electrode boundary film portion 1W.
Moreover, the oxygen electrode current collecting layer 2p is made larger than the oxygen electrode catalyst layer 2c, the periphery of the oxygen electrode current collector layer 2p is shifted from the periphery of the oxygen electrode catalyst layer 2c, and the fuel electrode current collector layer 3p is made fuel. Since the periphery of the fuel electrode current collecting layer 3p is shifted from the periphery of the fuel electrode catalyst layer 3c so as to be larger than the electrode catalyst layer 3c, the periphery of the oxygen electrode current collector layer 2p and the periphery of the oxygen electrode catalyst layer 2c And the stress applied to the electrode boundary film portion 1W in the polymer film 1 is further reduced as compared with the case where the periphery of the fuel electrode current collecting layer 3p and the periphery of the fuel electrode catalyst layer 3c overlap. It is configured.
[0077]
[Another embodiment]
Next, another embodiment will be described.
(A) In each of the first and second embodiments described above, the case where both the oxygen electrode side reinforcing member and the fuel electrode side reinforcing member are provided is illustrated. However, the oxygen electrode side reinforcing member and the fuel electrode side reinforcing member Only one of them may be provided.
[0078]
(B) In each of the above embodiments, the membrane portion corresponding to the peripheral portion of the oxygen electrode catalyst layer 2 c in the polymer membrane 1, that is, the oxygen electrode boundary membrane portion, and the fuel electrode catalyst layer 3 c in the polymer membrane 1 The case where the membrane portion corresponding to the peripheral portion, that is, the fuel electrode boundary membrane portion is configured so that the positions in the surface direction of the polymer film 1 coincide with each other has been illustrated, but the oxygen electrode boundary membrane portion and the fuel electrode boundary membrane You may comprise so that the position in the surface direction of the polymer film 1 may differ with a part.
In this case, as in each of the first and second embodiments, both the oxygen electrode side reinforcing member and the fuel electrode side reinforcing member may be provided. Of the oxygen electrode side reinforcing member and the fuel electrode side reinforcing member, Only one of them may be provided.
Further, both the oxygen electrode boundary membrane part and the fuel electrode boundary film part in the polymer film 1 may be reinforced by the fibrous reinforcing material 1r so that the strength is stronger than the other parts. Only one of the oxygen electrode boundary film part and the fuel electrode boundary film part in FIG. 6 may be reinforced with the fibrous reinforcing material 1r so that the strength is stronger than the other parts.
[0079]
(C) In each of the above embodiments, the polymer membrane 1, the oxygen electrode catalyst layer 2c, and the fuel electrode catalyst layer 3c are hot-pressed and joined to form an electrode-membrane assembly. However, the polymer membrane 1, the oxygen electrode catalyst layer 2c, the oxygen electrode current collector layer 2p, the fuel electrode catalyst layer 3c, and the fuel electrode current collector layer 3p are hot-pressed to join them together, thereby forming an electrode-membrane assembly. May be formed.
[0080]
(D) In each of the above embodiments, the oxygen electrode sealing member 6 and the fuel electrode sealing member 7 may be omitted. In that case, in the first embodiment, the oxygen electrode side separator 8 is brought into close contact with the oxygen electrode side reinforcing material 4 of the cell C adjacent thereto, and the fuel electrode side separator 9 is connected to the fuel electrode side reinforcing material 5 of the cell C adjacent thereto. Will be in close contact. Further, in each of the second to fourth embodiments, the oxygen electrode side separator 8 is brought into close contact with the exposed portion of the polymer film 1 of the cell C adjacent thereto, and the fuel electrode side separator 9 is set to the height of the cell C adjacent thereto. The molecular film 1 is brought into close contact with the exposed portion.
[0081]
(E) In the second embodiment, the oxygen electrode side reinforcing member 1s and the fuel electrode side reinforcing member 1f are illustrated as being integrally formed with the polymer film 1, but the oxygen electrode side reinforcing member 1s and the fuel are formed. The pole-side reinforcing member 1 f may be separated from the polymer film 1. In that case, the materials of the oxygen electrode side reinforcing member 1s and the fuel electrode side reinforcing member 1f may be different from the material of the polymer membrane 1.
[0082]
(F) A cell C is formed by combining any two or all of the characteristic configuration according to claim 1, the characteristic configuration according to claim 2, and the characteristic configuration according to claim 3. Also good. Further, the cell C may be configured by combining any two or all of the characteristic configuration according to claim 1, the characteristic configuration according to claim 2, and the characteristic configuration according to claim 4. good.
[0083]
(G) The form for supplying moisture for wetting the polymer membrane 1 to the cell C is the form exemplified in the above embodiment, that is, the oxygen electrode side reaction gas or the fuel electrode side reaction supplied to the cell C. It is not limited to a mode in which the working gas is humidified by a humidifier provided outside and the moisture is supplied using the oxygen electrode side reaction gas or the fuel electrode side reaction gas as a medium.
For example, the oxygen electrode side separator 8 and the fuel electrode side separator 9 are made of a porous material that can pass water, and the pressure of the cooling water flowing through the cooling water flow path w is changed to the oxygen electrode side gas flow path s and the fuel electrode. The pressure of each reaction gas flowing through each of the side gas flow paths f is set higher than that of a part of the cooling water flowing through the cooling water flow path w to the oxygen electrode side gas flow path s side or the fuel electrode side gas flow. It is good also as a form which supplies a water | moisture content directly to the cell C by making each separator 8 and 9 permeate | transmit to the path f side.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view in the thickness direction of a cell of a polymer electrolyte fuel cell according to a first embodiment.
FIG. 2 is an exploded perspective view of a cell of the polymer electrolyte fuel cell according to the first embodiment.
FIG. 3 is a cross-sectional view of the main part of the cell stack of the polymer electrolyte fuel cell according to the first embodiment.
FIG. 4 is a cross-sectional view in the thickness direction of a cell of a polymer electrolyte fuel cell according to a second embodiment.
FIG. 5 is an exploded perspective view of a cell of a polymer electrolyte fuel cell according to a second embodiment.
FIG. 6 is a cross-sectional view of a main part of a cell stack of a polymer electrolyte fuel cell according to a second embodiment.
FIG. 7 is a cross-sectional view in the thickness direction of a cell of a polymer electrolyte fuel cell according to a third embodiment.
FIG. 8 is an exploded perspective view of a cell of a polymer electrolyte fuel cell according to a third embodiment.
FIG. 9 is a cross-sectional view of a main part of a cell stack of a polymer electrolyte fuel cell according to a third embodiment.
FIG. 10 is a cross-sectional view in the thickness direction of a cell of a polymer electrolyte fuel cell according to a fourth embodiment.
FIG. 11 is an exploded perspective view of a cell of a polymer electrolyte fuel cell according to a fourth embodiment.
FIG. 12 is a cross-sectional view of a main part of a cell stack of a polymer electrolyte fuel cell according to a fourth embodiment.
FIG. 13 is an exploded perspective view of the main part of the cell stack of the polymer electrolyte fuel cell according to the embodiment.
FIG. 14 is an exploded perspective view of a main part of a cell stack of a polymer electrolyte fuel cell according to an embodiment.
FIG. 15 is an exploded perspective view of a main part of a cell stack of a polymer electrolyte fuel cell according to an embodiment.
FIG. 16 is a side view showing an overall schematic configuration of a cell stack of a polymer electrolyte fuel cell according to an embodiment.
FIG. 17 is a graph showing a change in the output voltage of the cell over time.
FIG. 18 is a cross-sectional view in the thickness direction of a cell of a conventional polymer electrolyte fuel cell
FIG. 19 is an exploded perspective view of a cell of a conventional polymer electrolyte fuel cell.
FIG. 20 is a cross-sectional view of a main part of a cell stack of a conventional polymer electrolyte fuel cell.
[Explanation of symbols]
1 Polymer membrane
1f, 1s reinforcement member
1r Fibrous reinforcement
2c Oxygen electrode catalyst layer
3c Fuel electrode catalyst layer
4,5 Reinforcing member
8,9 Channel forming member
f Fuel electrode side gas flow path
s Oxygen electrode side gas flow path
C cell

Claims (5)

電解質層としての高分子膜の一方の面にその周部を露出する状態で酸素極触媒層を備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層を備えた固体高分子型燃料電池のセルであって、
前記酸素極触媒層における前記高分子膜存在側とは反対側又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、弾性変形自在な補強部材が、前記高分子膜の厚さ方向に印加される押圧力により弾性変形して、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する膜部分に応力が集中するのを抑制するように、前記酸素極触媒層又は前記燃料極触媒層の周縁内外にわたる状態で設けられ、
さらに、前記酸素極触媒層における前記高分子膜存在側とは反対側、又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、前記酸素極触媒層より大きな酸素極集電層、又は前記燃料極触媒層より大きな燃料極集電層を備え、
前記酸素極触媒層の周縁と前記酸素極集電層の周縁、又は前記燃料極触媒層の周縁と前記燃料極集電層の周縁とがずれるように構成され、
前記酸素極集電層が前記酸素極触媒層と前記補強部材とに接触、又は前記燃料極集電層が前記燃料極触媒層と前記補強部材とに接触している固体高分子型燃料電池のセル。A solid high electrode comprising an oxygen electrode catalyst layer with its peripheral portion exposed on one surface of a polymer membrane as an electrolyte layer and a fuel electrode catalyst layer with its peripheral portion exposed on the other surface. A molecular fuel cell,
On the opposite side of the oxygen electrode catalyst layer to the polymer film existence side or the fuel electrode catalyst layer on the opposite side to the polymer film existence side, an elastically deformable reinforcing member is provided with a thickness of the polymer film. The elastic deformation is caused by the pressing force applied in the direction so as to suppress the concentration of stress on the peripheral portion of the oxygen electrode catalyst layer or the membrane portion corresponding to the peripheral portion of the fuel electrode catalyst layer in the polymer membrane. Are provided in a state over the inside and outside of the periphery of the oxygen electrode catalyst layer or the fuel electrode catalyst layer ,
Further, an oxygen electrode current collecting layer larger than the oxygen electrode catalyst layer on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or the side opposite to the polymer film existing side in the fuel electrode catalyst layer Or an anode current collecting layer larger than the anode electrode catalyst layer,
The peripheral edge of the oxygen electrode catalyst layer and the peripheral edge of the oxygen electrode current collector layer, or the peripheral edge of the fuel electrode catalyst layer and the peripheral edge of the fuel electrode current collector layer are configured to deviate,
In the polymer electrolyte fuel cell, the oxygen electrode current collecting layer is in contact with the oxygen electrode catalyst layer and the reinforcing member, or the fuel electrode current collecting layer is in contact with the fuel electrode catalyst layer and the reinforcing member . cell. 電解質層としての高分子膜の一方の面にその周部を露出する状態で酸素極触媒層を備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層を備えた固体高分子型燃料電池のセルであって、
前記高分子膜と前記酸素極触媒層との間又は前記高分子膜と前記燃料極触媒層との間に、弾性変形自在な補強部材が、前記高分子膜の厚さ方向に印加される押圧力により弾性変形して、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する膜部分に応力が集中するのを抑制するように、前記酸素極触媒層又は前記燃料極触媒層の周縁内外にわたる状態で設けられ、
さらに、前記酸素極触媒層における前記高分子膜存在側とは反対側、又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、前記酸素極触媒層より大きな酸素極集電層、又は前記燃料極触媒層より大きな燃料極集電層を備え、
前記酸素極触媒層の周縁と前記酸素極集電層の周縁、又は前記燃料極触媒層の周縁と前記燃料極集電層の周縁とがずれるように構成され、
前記酸素極集電層が前記酸素極触媒層と前記補強部材とに接触、又は前記燃料極集電層が前記燃料極触媒層と前記補強部材とに接触している固体高分子型燃料電池のセル。A solid high electrode comprising an oxygen electrode catalyst layer with its peripheral portion exposed on one surface of a polymer membrane as an electrolyte layer and a fuel electrode catalyst layer with its peripheral portion exposed on the other surface. A molecular fuel cell,
An elastically deformable reinforcing member is applied between the polymer film and the oxygen electrode catalyst layer or between the polymer film and the fuel electrode catalyst layer in the thickness direction of the polymer film. The oxygen electrode catalyst is elastically deformed by pressure so as to suppress stress concentration on a membrane portion corresponding to a peripheral portion of the oxygen electrode catalyst layer or a peripheral portion of the fuel electrode catalyst layer in the polymer membrane. A layer or a state extending across the periphery of the anode catalyst layer ,
Further, an oxygen electrode current collecting layer larger than the oxygen electrode catalyst layer on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or the side opposite to the polymer film existing side in the fuel electrode catalyst layer Or an anode current collecting layer larger than the anode electrode catalyst layer,
The peripheral edge of the oxygen electrode catalyst layer and the peripheral edge of the oxygen electrode current collector layer, or the peripheral edge of the fuel electrode catalyst layer and the peripheral edge of the fuel electrode current collector layer are configured to deviate,
In the polymer electrolyte fuel cell, the oxygen electrode current collecting layer is in contact with the oxygen electrode catalyst layer and the reinforcing member, or the fuel electrode current collecting layer is in contact with the fuel electrode catalyst layer and the reinforcing member . cell. 電解質層としての高分子膜の一方の面にその周部を露出する状態で酸素極触媒層を備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層を備えた固体高分子型燃料電池のセルであって、
前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する部分に、繊維状補強材を前記酸素極触媒層又は前記燃料極触媒層の周縁に対して内外方向にわたって混入することにより、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する部分の強度が他の部分よりも強くなるように構成され、
さらに、前記酸素極触媒層における前記高分子膜存在側とは反対側、又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、前記酸素極触媒層より大きな酸素極集電層、又は前記燃料極触媒層より大きな燃料極集電層を備え、
前記酸素極触媒層の周縁と前記酸素極集電層の周縁、又は前記燃料極触媒層の周縁と前記燃料極集電層の周縁とがずれるように構成され、
前記酸素極集電層が前記酸素極触媒層と前記高分子膜における前記酸素極触媒層の周縁部に対応する部分とに接触、又は前記燃料極集電層が前記燃料極触媒層と前記高分子膜における前記燃料極触媒層の周縁部に対応する部分とに接触している固体高分子型燃料電池のセル。A solid high electrode comprising an oxygen electrode catalyst layer with its peripheral portion exposed on one surface of a polymer membrane as an electrolyte layer and a fuel electrode catalyst layer with its peripheral portion exposed on the other surface. A molecular fuel cell,
A fibrous reinforcing material is applied to the periphery of the oxygen electrode catalyst layer or the periphery of the fuel electrode catalyst layer on the periphery of the oxygen electrode catalyst layer or the fuel electrode catalyst layer. By mixing over the direction, the polymer membrane is configured such that the strength of the portion corresponding to the peripheral portion of the oxygen electrode catalyst layer or the peripheral portion of the fuel electrode catalyst layer is stronger than the other portions ,
Further, an oxygen electrode current collecting layer larger than the oxygen electrode catalyst layer on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or the side opposite to the polymer film existing side in the fuel electrode catalyst layer Or an anode current collecting layer larger than the anode electrode catalyst layer,
The peripheral edge of the oxygen electrode catalyst layer and the peripheral edge of the oxygen electrode current collector layer, or the peripheral edge of the fuel electrode catalyst layer and the peripheral edge of the fuel electrode current collector layer are configured to deviate,
The oxygen electrode current collecting layer is in contact with the oxygen electrode catalyst layer and a portion of the polymer film corresponding to the peripheral edge of the oxygen electrode catalyst layer, or the fuel electrode current collecting layer is in contact with the fuel electrode catalyst layer and the high electrode layer. A cell of a polymer electrolyte fuel cell that is in contact with a portion of a molecular membrane corresponding to a peripheral portion of the fuel electrode catalyst layer . 電解質層としての高分子膜の一方の面にその周部を露出する状態で酸素極触媒層を備え、且つ、他方の面にその周部を露出する状態で燃料極触媒層を備えた固体高分子型燃料電池のセルであって、
前記高分子膜の全体にわたって混入する繊維状補強材の混入率を、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する部分を他の部分よりも高くすることにより、前記高分子膜における前記酸素極触媒層の周縁部又は前記燃料極触媒層の周縁部に対応する部分の強度が他の部分よりも強くなるように構成され、
さらに、前記酸素極触媒層における前記高分子膜存在側とは反対側、又は前記燃料極触媒層における前記高分子膜存在側とは反対側に、前記酸素極触媒層より大きな酸素極集電層、又は前記燃料極触媒層より大きな燃料極集電層を備え、
前記酸素極触媒層の周縁と前記酸素極集電層の周縁、又は前記燃料極触媒層の周縁と前記燃料極集電層の周縁とがずれるように構成され、
前記酸素極集電層が前記酸素極触媒層と前記高分子膜における前記酸素極触媒層の周縁部に対応する部分とに接触、又は前記燃料極集電層が前記燃料極触媒層と前記高分子膜における前記燃料極触媒層の周縁部に対応する部分とに接触している固体高分子型燃料電池のセル。A solid high electrode comprising an oxygen electrode catalyst layer with its peripheral portion exposed on one surface of a polymer membrane as an electrolyte layer and a fuel electrode catalyst layer with its peripheral portion exposed on the other surface. A molecular fuel cell,
The mixing rate of the fibrous reinforcing material mixed throughout the polymer membrane is set so that the portion corresponding to the peripheral portion of the oxygen electrode catalyst layer or the peripheral portion of the fuel electrode catalyst layer in the polymer membrane is higher than the other portions. By increasing the height, the polymer membrane is configured such that the strength of the portion corresponding to the peripheral portion of the oxygen electrode catalyst layer or the peripheral portion of the fuel electrode catalyst layer is stronger than the other portions ,
Further, an oxygen electrode current collecting layer larger than the oxygen electrode catalyst layer on the side opposite to the polymer film existing side in the oxygen electrode catalyst layer or the side opposite to the polymer film existing side in the fuel electrode catalyst layer Or an anode current collecting layer larger than the anode electrode catalyst layer,
The peripheral edge of the oxygen electrode catalyst layer and the peripheral edge of the oxygen electrode current collector layer, or the peripheral edge of the fuel electrode catalyst layer and the peripheral edge of the fuel electrode current collector layer are configured to deviate,
The oxygen electrode current collecting layer is in contact with the oxygen electrode catalyst layer and a portion of the polymer film corresponding to the peripheral edge of the oxygen electrode catalyst layer, or the fuel electrode current collecting layer is in contact with the fuel electrode catalyst layer and the high electrode layer. A cell of a polymer electrolyte fuel cell that is in contact with a portion of a molecular membrane corresponding to a peripheral portion of the fuel electrode catalyst layer . 請求項１〜４のいずれか１項に記載の固体高分子型燃料電池のセルの複数が、隣接するセル間に流路形成部材を位置させた状態で、厚さ方向に並置され、
前記流路形成部材が、その一方側に隣接する前記セルにおける前記酸素極触媒層の周縁部に対応する外周部に密着されて、前記セルとの間に酸素極側ガス流路を形成し、他方側に隣接する前記セルにおける前記燃料極触媒層の周縁部に対応する外周部に密着されて、前記セルとの間に燃料極側ガス流路を形成するように構成されている固体高分子型燃料電池。A plurality of cells of the polymer electrolyte fuel cell according to any one of claims 1 to 4 are juxtaposed in the thickness direction with a flow path forming member positioned between adjacent cells,
The flow path forming member is closely attached to an outer peripheral portion corresponding to a peripheral edge portion of the oxygen electrode catalyst layer in the cell adjacent to one side thereof, and forms an oxygen electrode side gas flow path between the cell and the cell, A solid polymer that is in close contact with the outer peripheral portion corresponding to the peripheral portion of the fuel electrode catalyst layer in the cell adjacent to the other side, and that forms a fuel electrode side gas flow path between the cells. Type fuel cell.
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