JP4008764B2 - Manufacturing method of fuel cell separator - Google Patents

Description

【００５５】
第１比較例は、第１セパレータとアノード側電極拡散層とを一体化しないで、第１セパレータにアノード側電極拡散層を合わせて接触させたものである。
第１実施例は、第１セパレータとアノード側電極拡散層とを一体化した第１実施形態のものである。
【００５６】
第１比較例と第１実施例との抵抗過電圧を以下の条件で測定した。
すなわち、セルモジュールの温度を８０℃に設定し、アノードガス（燃料ガス）として純Ｈ_２を供給するとともに、カソードガス（酸化剤ガス）として空気を供給した。
なお、アノード側の燃料ガス温度を８０℃、カソード側の酸化剤ガス温度を８０℃とし、アノード側の燃料ガス圧力を５０ｋＰａ、カソード側の酸化剤ガス圧力を１００ｋＰａとした。この条件下において、電流密度が０．８８３Ａ／ｃｍ^２の電流を流した。
【００５７】
この結果、第１実施例の抵抗過電圧を、第１比較例の抵抗過電圧と比較して、１セルモジュール当たり０．０１４Ｖ減らすことができた。
よって、第１実施例（第１実施形態）のように、第１セパレータとアノード側電極拡散層とを一体化することにより、抵抗過電圧を減らして燃料電池の出力低下を防ぐことができることが分かる。
【００５８】
次に、第２実施形態及び第４実施形態について説明する。なお、第２、第３実施形態において第１実施形態と同一部材については同一符号を付して説明を省略する。
図９（ａ）〜（ｃ）は本発明に係る燃料電池用セパレータの製造方法（第２実施形態）を説明する工程図である。
（ａ）において、中子成形型７６を型締めした状態で、中子成形型７６のキャビティ７６ａ内に、溶融状態の水溶性ポリマーを矢印▲３▼の如く充填する。水溶性ポリマーを凝固させて中子５０を成形した後、可動型７７を矢印の如く上昇する。
【００５９】
（ｂ）において、可動型７７を上昇することで型開きした中子成形型７６のキャビティ７６ａ内から中子５０を取り出す。
（ｃ）において、金型６０の固定型６１に中子５０をセットし、中子５０をセットした後、中子５０にアノード側電極拡散層１５を矢印の如く載せる。このように、中子５０や、アノード側電極拡散層１５をキャビティ６３内にセットした後、可動型６２を矢印の如く下降して金型６０を型締めする。
【００６０】
これにより、第１実施形態の図６（ｂ）の状態になる。以下、第１実施形態と同様の工程を順次繰り返すことにより、図１に示すアノード側電極拡散層１５に一体に形成した第１セパレータ２０を得ることができる。
さらに、図９と同様の工程で、図１に示すカソード側電極拡散層３５に一体に形成した第２セパレータ４０を得ることができる。
【００６１】
第２実施形態によれば、第１実施形態と同様の効果を得ることができる。
また、第２実施形態の燃料電池用セパレータの製造方法によれば、中子５０をアノード側電極拡散層１５と個別に成形することができる。これにより、中子５０の成形方法を第１、第２実施形態のうちのいずれか一方から適宜選択することができるので、設計の自由度を高めることができる。
【００６２】
次に、第３実施形態を図１０〜図１６に基づいて説明する。
図１０は本発明に係る燃料電池用セパレータ（第３実施形態）を備えた燃料電池の分解斜視図を示す。
燃料電池８０は、電解質膜１２にアノード側電極１３及びカソード側電極１４を添わせ、アノード側電極１３側にアノード側電極拡散層１５を介してセパレータ（燃料電池用セパレータ）８２を合わせるとともに、カソード側電極１４側にカソード側電極拡散層３５を介してセパレータ８２を合わせることによりセルモジュール８１を構成したものである。
【００６３】
図１１は図１０の１１−１１線断面図である。
セパレータ８２は、燃料ガス通路形成面（セパレータの両面のうちの一方の面）８２ａ側にアノード側電極拡散層１５を一体に成形することで、燃料ガス通路形成面８２ａ側に燃料ガス通路（ガス通路）８４・・・を多数本条形成する。
【００６４】
また、セパレータ８２は、酸化剤ガス通路形成面（セパレータの両面のうちの他方の面）８２ｂ側にカソード側電極拡散層３５を一体に成形することで、酸化剤ガス通路形成面８２ｂ側に酸化剤ガス通路（ガス通路）８６・・・を多数本条形成する。
さらに、セパレータ８２は、燃料ガス通路８３・・・及び酸化剤ガス通路８４・・・間に冷却水通路８５・・・を多数本条備える。
【００６５】
セパレータ８２を構成する樹脂としては、第１実施形態と同様に、一例として耐酸性を備えた熱可塑性樹脂に、天然黒鉛、人造黒鉛、ケッチェンブラック、アセチレンブラックなどを単独或いは混合配合し、炭素材料を６０〜９０ｗｔ％含んだ樹脂組成物が該当する。
【００６６】
耐酸性を備えた熱可塑性樹脂としては、例えばエチレン・酢ビ（酢酸ビニル）共重合体、エチレン・エチルアクリレート共重合体、直鎖状低密度ポリエチレン、ポリフェニレンサルファイド、変性ポリフェニレンオキサイドなどが該当するが、これに限定するものではない。
【００６７】
図１０に戻って、燃料ガス通路８３・・・（図１１に示す）に、セパレータ８２の上端左側の燃料ガス供給孔部９１ａを連通するとともに、セパレータ８２の下端右側の燃料ガス排出孔部９１ｂを連通する。
また、酸化剤ガス通路８４・・・（図１１も参照）に、セパレータ８２の上端右側の酸化剤ガス供給孔部９２ａを連通するとともに、セパレータ８２の下端左側の酸化剤ガス排出孔部９２ｂを連通する。
さらに、冷却水通路８５・・・（図１１に示す）に、セパレータ８２の上端中央の冷却水供給孔部９３ａを連通するとともに、セパレータ８２の下端中央に冷却水排出孔部９３ｂを連通する。
【００６８】
すなわち、第３実施形態の燃料電池用セパレータ８２は、燃料ガス通路８３・・・と酸化剤ガス通路８４・・・との間に冷却水通路８５・・・を成形することで、第１実施形態の第１、第２セパレータ２０，４０を一体成形した点で、第１実施形態と異なるだけで、その他の構成は第１実施形態と同じである。
このように、第１、第２セパレータ２０，４０を一体成形することで、一対のセパレータ２０，４０間に発生する電気的な接触抵抗をなくして、燃料電池の出力低下をより好適に防ぐことができる。
【００６９】
次に、燃料電池用セパレータの製造方法を図１２〜図１６に基づいて説明する。
先ず、図１２〜図１４に基づいて水溶性ポリマーで燃料ガス通路８３・・・、酸化剤ガス通路８４・・・及び冷却水通路８５・・・（図１１に示す）を形成するための中子１００（図１４に示す）を成形する工程について説明する。
なお、中子１００は、第１ガス通路用中子、第２ガス通路用中子及び冷却水通路用中子からなり、第１ガス通路用中子、第２ガス通路用中子及び冷却水通路用中子の製造工程を以下に説明する。
【００７０】
なお、中子１００は、第１実施形態と同様に水溶性ポリマーで成型する。水溶性ポリマーとしては、例えばポリアクリルアミド、ポリアクリル酸、ポリメタクリル酸、ポリイタコン酸、ポリビニルアルコールなどが該当するが、これに限るものではない。
すなわち、水溶性ポリマーとしては、中子として使用することが可能で、水溶性を備えたものであればよい。
【００７１】
図１２（ａ）〜（ｃ）は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第１工程図であり、燃料ガス通路８３・・・（図１１に示す）の第１ガス通路用中子を成形する例について説明する。
（ａ）において、中子成形型８６を型開きした状態で、可動型８７にアノード側電極拡散層１５をセットした後、可動型８７を矢印の如く固定型８８に向けて下降して中子成形型８６を型締めする。
【００７２】
（ｂ）において、中子成形型８６のキャビティ８６ａ内に、溶融状態の水溶性ポリマーを矢印▲４▼の如く充填する。水溶性ポリマーを凝固させて、第１ガス通路用中子１０１をアノード側電極拡散層１５と一体に成形（すなわち、一体化）した後、可動型８７を矢印の如く上昇する。
【００７３】
（ｃ）において、可動型８７を上昇することで型開きした中子成形型８６のキャビティ８６ａ内から、アノード側電極拡散層１５に一体に成形した第１ガス通路用中子１０１を取り出す。
【００７４】
一方、図１２の工程と同様の工程で、酸化剤ガス通路８４・・・（図１１に示す）の第２ガス通路用中子１０５（図１４参照）をカソード側電極拡散層３５と一体に成形することができる。
なお、燃料ガス通路８３・・・の第１ガス通路用中子１０１及びアノード側電極拡散層１５と、酸化剤ガス通路８４・・・の第２ガス通路用中子１０５及びカソード側電極拡散層３５については図１４で詳説する。
【００７５】
図１３（ａ），（ｂ）は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第２工程図であり、冷却水通路８５・・・（図１１に示す）の冷却水通路用中子を成形する例について説明する。
（ａ）において、中子成形型９７を型締めした状態で、中子成形型９７のキャビティ９７ａ内に、溶融状態の水溶性ポリマーを矢印▲５▼の如く充填する。水溶性ポリマーを凝固させて冷却水通路用中子１１１を成形した後、可動型９７を矢印の如く上昇する。
【００７６】
（ｂ）において、可動型９７を上昇することで型開きした中子成形型９６のキャビティ９７ａ内から冷却水通路用中子１１１を取り出す。
なお、成形した冷却水通路８５・・・の冷却水通路用中子１１１については図１４で詳説する。
【００７７】
図１４は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）に使用する中子（第１、第２ガス通路用中子及び冷却水通路用中子）の斜視図である。
アノード側電極拡散層１５は、一端側に燃料ガス供給孔部１６ａ、冷却水供給孔部１８ａ及び酸化剤ガス供給孔部１７ａを備え、他端側に燃料ガス排出孔部１６ｂ、冷却水排出孔部１８ｂ及び酸化剤ガス排出孔部１７ｂを備える。
このアノード側電極拡散層１５に第１ガス通路用中子１０１が一体に成形されている。
【００７８】
すなわち、第１ガス通路用中子１０１は、燃料ガス供給孔部１６ａに燃料ガス供給孔中子１０２を備え、燃料ガス排出孔部１６ｂに燃料ガス排出孔中子１０３を備える。
これらの燃料ガス供給孔中子１０２及び燃料ガス排出孔中子１０３に燃料ガス通路中子１０４を一体成形することで第１ガス通路用中子１０１を得る。なお、燃料ガス通路中子１０４はアノード側電極拡散層１５に一体に成形されている。
これにより、アノード側電極拡散層１５及び第１ガス通路用中子１０１を一体にまとめることができる。
【００７９】
カソード側電極拡散層３５は、一端側に燃料ガス供給孔部３６ａ、冷却水供給孔部３８ａ及び酸化剤ガス供給孔部３７ａを備え、他端側に燃料ガス排出孔部３６ｂ、冷却水排出孔部３８ｂ及び酸化剤ガス排出孔部３７ｂを備える。
このカソード側電極拡散層３５に第２ガス通路用中子１０５が一体に成形されている。
【００８０】
すなわち、第２ガス通路用中子１０５は、酸化剤ガス供給孔部３７ａに酸化剤ガス供給孔中子１０６を備え、酸化剤ガス排出孔部３７ｂに酸化剤ガス排出孔中子１０７を備える。
これらの酸化剤ガス供給孔中子１０６及び酸化剤ガス排出孔中子１０７に酸化剤ガス通路中子１０８を一体成形することで第２ガス通路用中子１０５を得る。なお、酸化剤ガス通路中子１０８はカソード側電極拡散層３５に一体に成形されている。
これにより、カソード側電極拡散層３５及び第２ガス通路用中子１０５を一体にまとめることができる。
【００８１】
第１ガス通路用中子１０１及び第２ガス通路用中子１０５間に配置する冷却水通路用中子１１１は、冷却水通路中子１１２の一端側に冷却水供給孔中子１１３を一体形成するとともに、他端側に冷却水排出孔中子１１４を一体成形したものである。
この冷却水供給孔中子１１３を、アノード側電極拡散層１５及びカソード側電極拡散層３５のそれぞれの冷却水供給孔部１８ａ，３８ａに嵌め込むとともに、アノード側電極拡散層１５及びカソード側電極拡散層３５のそれぞれの冷却水排出孔部１８ｂ，３８ｂに嵌め込む。
【００８２】
同時に、アノード側電極拡散層１５側の燃料ガス供給孔中子１０２及び燃料ガス排出孔中子１０３を、カソード側電極拡散層３５の燃料ガス供給孔部３６ａ及び燃料ガス排出孔部３６ｂにそれぞれ嵌め込む。
さらに、カソード側電極拡散層３５側の酸化剤ガス供給孔中子１０６及び酸化剤ガス排出孔中子１０７を、アノード側電極拡散層１５の酸化剤ガス供給孔部１７ａ及び酸化剤ガス排出孔部１７ｂにそれぞれ嵌め込む。
【００８３】
これにより、冷却水供給孔中子１１３及び冷却水排出孔中子１１４のそれぞれの下端１１３ａ，１１４ａがアノード側電極拡散層１５と面一になる。また、冷却水供給孔中子１１３及び冷却水排出孔中子１１４のそれぞれの上端１１３，１１４ｂがカソード側電極拡散層３５と面一になる。
【００８４】
また、燃料ガス供給孔中子１０２及び燃料ガス排出孔中子１０３のそれぞれの上端１０２ａ，１０３ａがカソード側電極拡散層３５と面一になる。
さらに、酸化剤ガス供給孔中子１０６及び酸化剤ガス排出孔中子１０７のそれぞれの下端１０６ａ，１０７ａがアノード側電極拡散層１５と面一になる。
【００８５】
次に、図１５〜図１６に基づいてセパレータを成形する工程について説明する。
図１５（ａ），（ｂ）は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第３工程図である。
（ａ）において、金型１２０の固定型１２１に第１ガス通路用中子１０１及びアノード側電極拡散層１５をセットし、第１ガス通路用中子１０１に冷却水通路用中子１１１を矢印の如く載せる。
次に、冷却水通路用中子１１１に第２ガス通路用中子１０５及びカソード側電極拡散層３５を矢印の如く載せた後、可動型１２２を矢印の如く下降して金型１２０を型締めする。
【００８６】
ここで、図１４に示すように、第２ガス通路用中子１０５及びカソード側電極拡散層３５を、酸化剤ガス供給孔中子１０６（図１４に示す）及び酸化剤ガス排出孔中子１０７でキャビティ面１２３ａに支えることができる。
また、冷却水通路用中子１１１を、冷却水供給孔中子１１３（図１４に示す）及び冷却水排出孔中子１１４でキャビティ１２３ａ面に支えることができる。
【００８７】
このように、第２ガス通路用中子１０５を酸化剤ガス供給孔中子１０６や酸化剤ガス排出孔中子１０７でキャビティ１２３内に配置するとともに、冷却水通路用中子１１１を冷却水供給孔中子１１３及び冷却水排出孔中子１１４でキャビティ１２３内に配置することができる。
よって、第２ガス通路用中子１０５や冷却水通路用中子１１１をキャビティ１２３内に配置するために通常必要とされるケレンなどの支え部材を不要にすることができる。
【００８８】
ケレンなどの支え部材を備えた場合には、キャビティ１２３内に樹脂を充填してセパレータを成形した後、ケレンなどの支え部材の部分がセパレータに隙間として残る虞がある。
その場合、残った隙間をシリコン剤などのシール剤で塞ぐ必要があるが、第３実施形態によればその必要はない。
【００８９】
（ｂ）において、金型１２０を型締めすることで、第１、第２ガス通路用中子１０１，１０５及び冷却水通路用中子１１１を金型１２０のキャビティ１２３内に配置する。第１ガス通路用中子１０１及びキャビティ面１２３ａ間の隙間にアノード側電極拡散層１５を配置するとともに、第２ガス通路用中子１０５及びキャビティ面１２３ｂ間の隙間にカソード側電極拡散層３５を配置する。
この状態で、キャビティ１２３内に溶融樹脂を矢印▲６▼の如く充填する。
【００９０】
図１６（ａ）〜（ｃ）は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第４工程図である。
（ａ）において、充填した溶融樹脂を凝固させてセパレータ８２を中子１００（第１、第２ガス通路用中子１０１，１０５及び冷却水通路用中子１１１）、アノード側電極拡散層１５及びカソード電極拡散層３５と一体形成した後、可動型を上昇して金型１２０を型開きする。
型開きした後、セパレータ８２、中子１００、アノード側電極拡散層１５及びカソード電極拡散層３５をキャビティ１２３内から取り出す。
【００９１】
（ｂ）において、セパレータ８２、中子１００、アノード側電極拡散層１５及びカソード電極拡散層３５を、水槽１２５に蓄えた水１２６中に漬ける。
これにより、中子１００を水１２６で溶かすことにより、セパレータ８２内から溶出する。
このように、中子１００を水溶性ポリマーで成形することで、中子１００を水１２６で溶出することができる。このため、中子１００を溶出する設備を簡単にすることができるので、設備費を抑えて、コスト低減を図ることができる。
【００９２】
（ｃ）において、セパレータ８２内から第１、第２ガス通路用中子１０１，１０５及び冷却水通路用中子１１１（（ｂ）に示す）を溶出することで、セパレータ８２に燃料ガス通路８３・・・、冷却水通路８５・・・及び酸化剤ガス通路８４・・・を開けることができる。
この状態で、水槽１２５内からセパレータ８２、アノード側電極拡散層１５及びカソード側電極拡散層３５を取り出すことにより、アノード側電極拡散層１５とカソード側電極拡散層３５間に一体形成したセパレータ８２を得る。
なお、このセパレータ８２は、図１１に示すセパレータ８２を反転した状態で示す。
【００９３】
以上説明した第３実施形態によれば、第１実施形態と同様の効果を得ることができる。すなわち、第３実施形態によれば、中子１００を水溶性ポリマーで形成し、この中子１００でセパレータ８２に燃料ガス通路８３・・・及び酸化剤ガス通路８４・・・を成形した。
これにより、セパレータ８２の成形後に中子１００を水１２６で溶出することで、燃料ガス通路８３・・・及び酸化剤ガス通路８４・・・を開けることができる。
【００９４】
このように、セパレータ８２内の中子１００を水１２６で溶出することができるので、セパレータ８２に燃料ガス通路８３・・・及び酸化剤ガス通路８４・・・を簡単に形成することができる。
【００９５】
さらに、セパレータ８２をアノード側電極拡散層１５及びカソード電極拡散層３５と一体形成した。これにより、セパレータ８２とアノード側電極拡散層１５との間の電気的な接触抵抗を抑えることができるとともに、セパレータ８２とカソード電極拡散層３５との間の電気的な接触抵抗を抑えることができるので、燃料電池の出力低下を防ぐことができる。
【００９６】
加えて、第３実施形態によれば、水溶性ポリマーの中子１００を利用してセパレータ８２内に冷却水通路８５・・・を形成することにした。セパレータ８２内に冷却水通路８５・・・を形成することができるので、従来技術のように一対のセパレータを重ね合わせて冷却水通路を形成する必要はない。
【００９７】
このように、従来必要とされていた一対のセパレータを一体成形することができるので、従来技術のように一対のセパレータ間に発生する電気的な接触抵抗を抑えることができる。
このように、接触抵抗を抑えることで、抵抗過電圧を減らして燃料電池の出力低下を防ぐことができる。
【００９８】
次に、第３実施形態の抵抗過電圧を表２に基づいて説明する。
【００９９】
【表２】

【０１００】
第２比較例は、第１セパレータと第２セパレータとを一体化しないで、第１セパレータに第２セパレータを合わせたものである。
第２実施例は、セパレータを一体化した第３実施形態のものである。
【０１０１】
第２比較例と第２実施例との抵抗過電圧を以下の条件で測定した。
すなわち、セルモジュールの温度を８０℃に設定し、アノードガス（燃料ガス）として純Ｈ_２を供給するとともに、カソードガス（酸化剤ガス）として空気を供給した。
なお、アノード側の燃料ガス温度を８０℃、カソード側の酸化剤ガス温度を８０℃とし、アノード側の燃料ガス圧力を５０ｋＰａ、カソード側の酸化剤ガス圧力を１００ｋＰａとした。この条件下において、電流密度が０．８８３Ａ／ｃｍ^２の電流を流した。
【０１０２】
この結果、第２実施例の抵抗過電圧を、第２比較例の抵抗過電圧と比較して、１セルモジュール当たり０．０２７Ｖ減らすことができた。
よって、第２実施例（第３実施形態）のように、セパレータを一体化することにより、抵抗過電圧を減らして燃料電池の出力低下を防ぐことができることが分かる。
【０１０３】
次に、第４実施形態について説明する。
第３実施形態では、図１４に示すように、第１ガス通路用中子１０１をアノード側電極拡散層１５と一体に成形し、第２ガス通路用中子１０５カソード側電極拡散層３５と一体に成形した例について説明したが、これに限らないで、第１ガス通路用中子１０１をアノード側電極拡散層１５から切り離して成形し、第２ガス通路用中子１０５カソード側電極拡散層３５から切り離して成形することも可能である。
【０１０４】
この場合、図１５に示す金型１２０のキャビティ１２３内に、先ず、アノード側電極拡散層１５を配置し、アノード側電極拡散層１５に第１ガス通路用中子１０１を載せる。この第１ガス通路用中子１０１に冷却水通路用中子１１１を載せ、冷却水通路用中子１１１に第２ガス通路用中子１０５を載せた後、第２ガス通路用中子１０５にカソード側電極拡散層３５を載せる。
【０１０５】
この状態で金型１２０を型閉めすることにより、第３実施形態の図１５（ｂ）と同様に、第１、第２ガス通路用中子１０１，１０５及び冷却水通路用中子１１１、アノード側電極拡散層１５及びカソード側電極拡散層３５をキャビティ１２３内にセットすることができる。
よって、第４実施形態においても、第３実施形態と同様の効果を得ることができる。
【０１０６】
加えて、第４実施形態の燃料電池用セパレータの製造方法によれば、第１ガス通路用中子１０１をアノード側電極拡散層１５と個別に成形することができ、かつ第２ガス通路用中子１０５をカソード側電極拡散層３５と個別に成形することができる。
これにより、第１、第２ガス通路用中子１０１，１０５の成形方法を第３、第４実施形態のうちのいずれか一方から適宜選択することができるので、設計の自由度を高めることができる。
【０１０７】
なお、前記実施形態では、電解質膜１２として固体高分子電解質を使用した固体高分子型燃料電池１０，８０について説明したが、これに限らないで、その他の燃料電池に適用することも可能である。
【０１０８】
また、前記第１、第２実施形態では、第１、第２セパレータ２０，４０を射出成形方法で成形する例について説明したが、これに限らないで、例えば加熱プレス成形方法やトランスファー成形方法で成形することも可能である。
トランスファー成形装置とは、成形材料をキャビティとは別のポット部に１ショット分入れ、プランジャーによって溶融状態の材料をキャビティに移送して成形する方法である。
【０１０９】
加熱プレス成形方法で第１、第２セパレータ２０，４０を成形する際には、第１、第２セパレータ２０，４０を構成する樹脂としては、一例として耐酸性を備えた熱硬化性樹脂に、天然黒鉛、人造黒鉛、ケッチェンブラック、アセチレンブラックなどを単独或いは混合配合し、炭素材料を６０〜９０ｗｔ％含んだ樹脂組成物が該当する。
耐酸性の有する熱硬化性樹脂としては、例えばフェノール、ビニルエステルなどが該当するが、これに限定するものではない。
【０１１０】
【発明の効果】
本発明は上記構成により次の効果を発揮する。
請求項１，２は、ガス通路を形成するための中子を水溶性ポリマーで形成し、セパレータの成形後に中子を水で溶出することで、ガス通路を形成することができる。
このように、セパレータ内の中子を水で溶出することができるので、セパレータにガス通路を簡単に形成することができ、セパレータを簡単に製造することができる。
【０１１１】
また、セパレータを電極拡散層と一体に形成することにした。これにより、セパレータと電極拡散層との間の電気的な接触抵抗を抑えることができるので、燃料電池の出力低下を防ぐことができる。
【０１１２】
請求項３は、ガス通路を形成するためのガス通路用中子を水溶性ポリマーで形成し、セパレータの成形後にガス通路用中子を水で溶出することで、ガス通路を形成することができる。
このように、セパレータ内のガス通路用中子を水で溶出することができるので、セパレータにガス通路を簡単に形成することができ、セパレータを簡単に製造することができる。
【０１１３】
また、セパレータを電極拡散層と一体に形成することにした。これにより、セパレータと電極拡散層との間の電気的な接触抵抗を抑えることができるので、燃料電池の出力低下を防ぐことができる。
【０１１４】
さらに、冷却水通路用中子を水溶性ポリマーで形成し、セパレータの成形後に冷却水通路用中子を水で溶出することで、セパレータ内に冷却水通路を形成することにした。セパレータ内に冷却水通路を形成することができるので、一対のセパレータを重ね合わせて冷却水通路を形成する必要はない。
このように、一対のセパレータを重ね合わせる必要がないので、従来技術のように一対のセパレータ間に発生する電気的な接触抵抗をなくして、燃料電池の出力低下を防ぐことができる。
【図面の簡単な説明】
【図１】本発明に係る燃料電池用セパレータ（第１実施形態）を備えた燃料電池の分解斜視図
【図２】図１の２−２線断面図
【図３】図１の３−３線断面図
【図４】本発明に係る燃料電池用セパレータの製造方法（第１実施形態）を説明する第１工程図
【図５】本発明に係る燃料電池用セパレータの製造方法（第１実施形態）に使用する中子の斜視図
【図６】本発明に係る燃料電池用セパレータの製造方法（第１実施形態）を説明する第２工程図
【図７】本発明に係る燃料電池用セパレータの製造方法（第１実施形態）を説明する第３工程図
【図８】図１の８−８線断面図
【図９】本発明に係る燃料電池用セパレータの製造方法（第２実施形態）を説明する工程図
【図１０】本発明に係る燃料電池用セパレータ（第３実施形態）を備えた燃料電池の分解斜視図
【図１１】図１０の１１−１１線断面図
【図１２】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第１工程図
【図１３】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第２工程図
【図１４】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）に使用する中子（第１、第２ガス通路用中子及び冷却水通路用中子）の斜視図
【図１５】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第３工程図
【図１６】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第４工程図
【図１７】従来の燃料電池を示す分解斜視図
【符号の説明】
１０，８０…燃料電池、１５…アノード側電極拡散層（電極拡散層）、２０…第１セパレータ（燃料電池用セパレータ）、２０ｂ…燃料ガス通路形成面（セパレータの表面）、２６，８３…燃料ガス通路（ガス通路）、３０，８５…冷却水通路、３５…カソード側電極拡散層（電極拡散層）、４０…第２セパレータ（燃料電池用セパレータ）、４０ｂ…酸化剤ガス通路形成面、４６，８４…酸化剤ガス通路（ガス通路）、５０，１００…中子、６０，１２０…金型、６３，１２３…キャビティ、６３ａ，６３ｂ，１２３ａ，１２３ｂ…キャビティ面、６６，１２６…水、８２…セパレータ（燃料電池用セパレータ）、８２ｂ…酸化剤ガス通路形成面（セパレータの両面の他方）、１０１…第１ガス通路用中子、１０５…第２ガス通路用中子、１１１…冷却水通路用中子、８２ａ…燃料ガス通路形成面（セパレータの両面の一方）。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a fuel cell separator that constitutes a cell module by attaching an anode side electrode and a cathode side electrode to an electrolyte membrane and sandwiching them from both sides.
[0002]
[Prior art]
A fuel cell is a battery that utilizes the reverse principle of water electrolysis and can obtain electricity in the process of obtaining water by reacting hydrogen and oxygen. In general, since the fuel gas is replaced by hydrogen and the air or oxidant gas is replaced by oxygen, the terms fuel gas, air, and oxidant gas are often used.
[0003]
As such a fuel cell, for example, Japanese Unexamined Patent Publication No. 2000-123848 “Fuel Cell” is known. The fuel cell will be described with reference to FIG.
FIG. 17 is an exploded perspective view showing a conventional fuel cell.
In the fuel cell 200, an anode-side electrode 202 and a cathode-side electrode 203 are attached to an electrolyte membrane 201, and these are sandwiched between a first separator 206 and a second separator 207 via gaskets 204 and 205 to constitute a cell module.
[0004]
Specifically, a first flow path 208 serving as a fuel gas flow path is formed on the surface 206a of the first separator 206, and a second flow path 209 serving as an oxidant gas flow path is formed on the surface 207a of the second separator 207. In this structure, the fuel gas and the oxidant gas are respectively exposed to the central electrolyte membrane 201.
[0005]
Since the electric output obtained by one cell module is very small, a desired electric output can be obtained by stacking a large number of such cell modules. Accordingly, the first and second separators 206 and 207 are called “separators” because they are separation members that prevent fuel gas and oxidant gas from leaking into adjacent cells.
[0006]
The first separator 206 is provided with a flow path 208 for fuel gas on the face 206a, and the second separator 207 is provided with a flow path 209 for oxidant gas on the face 207a. It is necessary to make contact with the cathode side electrode 203. For this reason, the flow paths 208 and 209 need to be provided with a number of extremely shallow grooves.
[0007]
The first and second separators 206 and 207 are respectively provided with a fuel gas supply hole 210a and an oxidant gas supply hole 211a in the upper part for supplying fuel gas or oxidant gas to the flow paths 208 and 209, respectively. A fuel gas discharge hole 210b and an oxidant gas discharge hole 211b are respectively provided at the lower part, a cooling water supply hole 212a for passing cooling water is provided at the upper part, and a cooling water discharge hole 212b is provided at the lower part. Prepare for.
[0008]
[Problems to be solved by the invention]
The cooling water supply hole 212a and the cooling water discharge hole 212b described above are respectively connected to a cooling water passage (not shown).
The cooling water passage, for example, forms a cooling water passage groove on each of the back surface of the surface 206a of the first separator 206 and the back surface of the surface 207a of the second separator 207, and the cooling water passage groove, It is formed by combining the grooves for cooling water passages provided in the separators of adjacent cells.
[0009]
When the cooling water passage is formed by combining the separators as described above, a sealing material for preventing leakage of the cooling water is required at the mating portion of the separator, and the thickness, shape, material, etc. of the sealing material are taken into consideration. There must be.
[0010]
In addition, a gas passage groove is provided on one surface of the first separator 206 or the second separator 207, and a cooling water passage groove is provided on the other surface, making it difficult to form each groove.
Further, in order to match the separators, the electrical contact resistance between the separators increases, the voltage of each cell drops due to this contact resistance, and the output of the fuel cell may be reduced.
[0011]
Accordingly, an object of the present invention is to provide a method of manufacturing a separator for a fuel cell, which can easily manufacture the separator and can suppress a decrease in the output of the fuel cell.
[0012]
[Means for Solving the Problems]
  In order to achieve the above object, claim 1 provides:A step of disposing an electrode diffusion layer in the cavity of the core mold, and a step of forming a core for forming a gas passage in the cavity integrally with the electrode diffusion layer with a water-soluble polymer; The step of taking out the formed core and the electrode diffusion layer from the core mold and placing it in the mold cavity, the step of filling the mold cavity with the molten resin, and the separator coagulating the molten resin Are formed integrally with the core and the electrode diffusion layer and then taken out from the cavity of the mold, and the core is dissolved in water and eluted from the separator, whereby the separator and the electrode diffusion layer The process for forming the gas passage constitutes a method of manufacturing a fuel cell separator.
  Claim 2Forming a core for forming a gas passage with a water-soluble polymer, placing the core in a cavity of the mold,In the cavityCoreInThe step of arranging the electrode diffusion layer, the step of filling the cavity with the molten resin, and the separator that solidifies the molten resin,SaidCore andSaidThe step of forming it integrally with the electrode diffusion layer and then removing it from the cavity, and the coreDissolved in waterBy eluting from the separator,SaidSeparator andSaidElectrode diffusion layerIn the aboveThe process for forming the gas passage constitutes a method of manufacturing a fuel cell separator.
[0013]
  According to claims 1 and 2,The gas passage can be formed by forming the core for forming the gas passage with a water-soluble polymer and eluting the core with water after molding the separator.
  Thus, since the core in the separator can be eluted with water, a gas passage can be easily formed in the separator.
[0014]
Here, the normal fuel cell includes an anode side electrode diffusion layer between the anode side electrode and the separator, and also includes a cathode side electrode diffusion layer between the cathode side electrode and the separator.
Thus, in order to match the anode side electrode diffusion layer to the separator and to match the cathode side electrode diffusion layer to the separator, the electrical contact resistance between the separator and the anode side electrode diffusion layer, It is considered that the typical contact resistance increases. Due to this contact resistance, the voltage of the fuel cell drops, and the output of the fuel cell may be reduced.
[0015]
  Therefore, claim 1, 2Therefore, the separator is formed integrally with the electrode diffusion layer. Thereby, the electrical contact resistance between a separator and an electrode diffusion layer can be suppressed.
[0016]
  Claim3IsArranging the electrode diffusion layer in the cavity of the core forming die for the gas passage;
  In the cavity, a step of forming a gas passage core for forming a gas passage integrally with the electrode diffusion layer with a water-soluble polymer, on the other hand, in the cavity of the cooling water passage core molding die,A cooling water passage core for forming the cooling water passageWater soluble polymerForming, andThe integrally formed gas passage core and electrode diffusion layer are taken out from the gas passage core mold and placed in a cavity of the mold, and the cooling is taken out from the cooling water path core mold. The water passage coreAt a predetermined interval from the gas passage coreIn the cavity of the moldArranging, andMoldThe step of filling the cavity with molten resin and the separator that solidifies the molten resin,SaidCore for gas passage,SaidCore for cooling water passage andSaidAfter forming integrally with the electrode diffusion layerMoldA step of removing from the cavity, and the core for the gas passage andSaidCore for cooling water passageEach is dissolved in waterBy eluting from the separator,SaidSeparator andSaidElectrode diffusion layersoForming a gas passage,SaidIn the separatorSaidThe manufacturing method of the separator for fuel cells is comprised from the process of forming a cooling water path.
[0017]
The gas passage core can be formed by forming a core for the gas passage for forming the gas passage with a water-soluble polymer and eluting the core for the gas passage with water after molding the separator.
Thus, since the core for gas passages in a separator can be eluted with water, a gas passage can be easily formed in a separator.
In addition, the separator is formed integrally with the electrode diffusion layer. Thereby, the electrical contact resistance between a separator and an electrode diffusion layer can be suppressed.
[0018]
Here, an ordinary separator forms a cooling water passage by combining a cooling water passage groove of one separator and a cooling water passage groove of the other separator by overlapping a pair of separators.
Thus, it is conceivable that the electrical contact resistance between the pair of separators is increased by overlapping the pair of separators. Due to this contact resistance, the voltage of the fuel cell drops, and the output of the fuel cell may be reduced.
[0019]
  Therefore, the claim3The cooling water core was formed of a water-soluble polymer, and the cooling water core was eluted with water after the separator was formed, thereby forming a cooling water passage in the separator. Since the cooling water passage can be formed in the separator, it is not necessary to form a cooling water passage by overlapping a pair of separators.
  Thus, since it is not necessary to overlap a pair of separator, the electrical contact resistance which generate | occur | produces between a pair of separator can be eliminated.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is an exploded perspective view of a fuel cell provided with a fuel cell separator (first embodiment) according to the present invention.
As an example, the fuel cell 10 uses a solid polymer electrolyte for the electrolyte membrane 12, the anode side electrode 13 and the cathode side electrode 14 are attached to the electrolyte membrane 12, and the anode side electrode diffusion layer 15 is provided on the anode side electrode 13 side. The cell module 11 is configured by aligning the first separator (separator) 20 via the cathode electrode 14 and the second separator (separator) 40 via the cathode electrode diffusion layer 35 on the cathode electrode 14 side. Is a polymer electrolyte fuel cell in which a large number of fuel cells are stacked.
[0021]
When stacking adjacent cell modules 11, 11, the first separator 20 constituting one cell module 11 and the second separator 40 constituting the other cell module 11 are cooled by the separators 20, 40. Align with the water passage forming surfaces 20a and 40a.
[0022]
Thereby, the cooling water passage grooves 21... Of the first separator 20 and the cooling water passage grooves 41... Of the second separator 40 form cooling water passages 30.
The cooling water passages 30... Communicate with cooling water supply holes 22 a and 42 a at the center of the upper ends of the first and second separators 20 and 30 and at the center of the lower ends of the first and second separators 20 and 40. The cooling water discharge holes 22b and 42b communicate with each other.
[0023]
The first separator 20 is formed by integrally molding (that is, integrating) the anode-side electrode diffusion layer (electrode diffusion layer) 15 on the fuel gas passage formation surface (separator surface) 20b side, so that the fuel gas passage formation surface 20b. Fuel gas passage grooves (gas passages) 23 (shown in FIG. 2) are formed on the side.
The fuel gas passage grooves 23... Communicate with the fuel gas supply holes 24 a and 44 a on the left side of the upper ends of the first and second separators 20 and 40 and on the right side of the lower ends of the first and second separators 20 and 40. The fuel gas discharge holes 24b and 44b are communicated.
[0024]
The second separator 40 integrally forms (that is, integrates) a cathode side electrode diffusion layer (electrode diffusion layer) 35 on the oxidant gas passage formation surface (separator surface) 40b side, thereby forming an oxidant gas passage. Oxidant gas passages (gas passages) 46... Shown in FIG.
The oxidant gas passages 46... Communicate with the oxidant gas supply holes 25 a and 45 a on the right side of the upper ends of the first and second separators 20 and 40 and the lower left sides of the first and second separators 20 and 40. The oxidant gas discharge holes 25b and 25b are communicated with each other.
[0025]
As a resin constituting the first and second separators 20 and 40, for example, a natural graphite, artificial graphite, ketjen black, acetylene black or the like is blended singly or in combination with a thermoplastic resin having acid resistance. Corresponds to a resin composition containing 60 to 90 wt%.
[0026]
Examples of the thermoplastic resin having acid resistance include ethylene / vinyl acetate (vinyl acetate) copolymer, ethylene / ethyl acrylate copolymer, linear low density polyethylene, polyphenylene sulfide, and modified polyphenylene oxide. However, the present invention is not limited to this.
[0027]
2 is a cross-sectional view taken along line 2-2 of FIG.
The first separator 20 is a member formed in a substantially rectangular shape as shown in FIG. 1, and has a plurality of fuel gas passage grooves 23 on the fuel gas passage forming surface 20b, and the fuel gas passage forming surface 20b. The anode side electrode diffusion layer 15 is integrally provided with the fuel gas passage groove 23 and the anode side electrode diffusion layer 15 to form the fuel gas passage 26 and the cooling water passage formation surface 20a is cooled. There are many water passage grooves 21.
[0028]
FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1, and the anode-side electrode diffusion layer 15 is integrally formed on the fuel gas passage forming surface 20b side of the first separator 20 so that the fuel gas passage groove 23 and the anode side are formed. A fuel gas passage 26 is formed in the electrode diffusion layer 15, and the fuel gas supply hole 24 a on the upper left side of the first separator 20 is communicated with the fuel gas passage 26.
[0029]
Next, the manufacturing method of the separator for fuel cells is demonstrated based on FIGS.
First, a process of forming the core 50 for forming the fuel gas passage 26 and the cooling water passage groove 21 with a water-soluble polymer will be described with reference to FIGS.
4 (a) to 4 (c) are first process diagrams illustrating a method for manufacturing a fuel cell separator (first embodiment) according to the present invention.
In (a), with the core forming die 56 opened, the anode side electrode diffusion layer 15 is set on the movable die 57, and then the movable die 57 is lowered toward the fixed die 58 as indicated by the arrow. The mold 56 is clamped.
[0030]
In (b), the melted water-soluble polymer is filled into the cavity 56a of the core mold 56 as shown by the arrow (1). After the water-soluble polymer is solidified and the core 5 is formed integrally with the anode-side electrode diffusion layer 15 (that is, integrated), the movable die 57 is raised as shown by an arrow.
[0031]
Examples of the water-soluble polymer include, but are not limited to, polyacrylamide, polyacrylic acid, polymethacrylic acid, polyitaconic acid, and polyvinyl alcohol. That is, any water-soluble polymer may be used as long as it can be used as a core and has water solubility.
[0032]
In (c), the core 50 molded integrally with the anode-side electrode diffusion layer 15 is taken out from the cavity 56a of the core mold 56 that is opened by raising the movable mold 57.
[0033]
FIG. 5 is a perspective view of the core used in the method for manufacturing a fuel cell separator according to the present invention (first embodiment). The anode-side electrode diffusion layer 15 taken out from the cavity 56a (shown in FIG. 4) and FIG. A core 50 formed integrally with the anode side electrode diffusion layer 15 is shown.
FIG. 5 shows a state in which the core 50 faces upward so that the shape of the core 50 can be easily understood.
[0034]
The anode-side electrode diffusion layer 15 includes a fuel gas supply hole 16a, a cooling water supply hole 18a, and an oxidant gas supply hole 17a on one end side, and a fuel gas discharge hole 16b and a cooling water discharge hole on the other end side. Part 18b and oxidant gas discharge hole 17b.
The fuel gas supply hole 16a, the cooling water supply hole 18a and the oxidant gas supply hole 17a are provided with a fuel gas supply hole core 51a, a cooling water supply hole core 52a and an oxidant gas supply hole core 53a.
[0035]
Further, the fuel gas discharge hole core 51b, the cooling water discharge hole core 52b and the oxidant gas discharge hole core 53b are provided in the fuel gas discharge hole portion 16b, the cooling water discharge hole portion 18b and the oxidant gas discharge hole portion 17b. Prepare.
The fuel gas passage core 54 is formed integrally with the anode side electrode diffusion layer 15, the supply side 54 a of the fuel gas passage core 54 is connected to the fuel gas supply hole core 51 a, and the fuel gas passage core 54 is discharged. The side 54b is connected to the fuel gas discharge hole core 51b.
[0036]
Accordingly, the anode side electrode diffusion layer 15, the fuel gas supply hole core 51a, the cooling water supply hole core 52a, the oxidant gas supply hole core 53a, the fuel gas discharge hole core 51b, and the cooling water discharge hole core 52b. The oxidant gas discharge hole core 53b and the fuel gas passage core 54 can be integrated together.
The fuel gas supply hole core 51a, the cooling water supply hole core 52a, the oxidant gas supply hole core 53a, the fuel gas discharge hole core 51b, the cooling water discharge hole core 52b, and the oxidant gas discharge hole core. 53 b and the fuel gas passage core 54 constitute a core 50.
[0037]
When the core 50 and the anode side electrode diffusion layer 15 are set in the cavity of the mold, the tip 51c of the fuel gas supply hole core 51a, the tip 52c of the cooling water supply hole core 52a, the oxidant gas supply The tip 53c of the hole core 53a, the tip 51e of the fuel gas discharge hole core 51b, the tip 52e of the coolant discharge hole core 52b, and the tip 53e of the oxidant gas discharge hole core 53b are placed on the cavity surface of the mold.
[0038]
Next, the process of forming the first separator will be described based on FIGS.
6 (a) and 6 (b) are second process diagrams illustrating a method for manufacturing a fuel cell separator (first embodiment) according to the present invention.
In (a), the core 50 and the anode side electrode diffusion layer 16 are set on the fixed mold 61 of the mold 60, and the movable mold 62 is lowered as indicated by the arrow to clamp the mold 60.
[0039]
As described with reference to FIG. 5, the core 50 includes the tip 51c of the fuel gas supply hole core 51a, the tip 52c of the cooling water supply hole core 52a, the tip 53c of the oxidant gas supply hole core 53a, the fuel gas discharge The tip 51e of the hole core 51b, the tip 52e of the cooling water discharge hole core 52b, and the tip 53e of the oxidant gas discharge hole core 53b are placed on the cavity surface 63a of the mold 60.
Thereby, the core 50 and the anode side electrode diffusion layer 15 can be set on the cavity surface 63 a of the fixed mold 61.
[0040]
In this way, the core 50 can be disposed in the cavity 63 by using the supply hole cores 51a, 52a, 53a and the discharge hole cores 51b, 52b, 53b. A supporting member such as keren, which is normally required for placement in 63, can be eliminated.
[0041]
When a support member such as keren is provided, there is a possibility that a portion of the support member such as kelen may remain as a gap in the separator after the cavity 63 is filled with resin and the separator is molded.
In that case, the remaining gap needs to be closed with a sealing agent such as a silicon agent, but according to the first embodiment, this is not necessary.
[0042]
In (b), by clamping the mold 60, the core 50 is disposed in the cavity 63 of the mold 60, and the anode-side electrode diffusion layer 15 is disposed in the gap between the core 50 and the cavity surface 63b. To do.
In this state, the cavity 63 is filled with molten resin as indicated by the arrow (2).
[0043]
FIGS. 7A to 7C are third process diagrams for explaining the method for manufacturing a fuel cell separator according to the present invention (first embodiment).
In (a), after the molten resin in the cavity is solidified to integrally form the first separator 20 with the core 50 and the anode side electrode diffusion layer 15, the movable mold 62 is raised to open the mold 60. The first separator 20, the core 50 and the anode side electrode diffusion layer 15 are taken out from the cavity 63.
[0044]
In (b), the first separator 20, the core 50 and the anode side electrode diffusion layer 15 are immersed in water 66 stored in the water tank 65. As a result, the core 50 is melted with water and the core 50 is eluted from the first separator 20.
By molding the core 50 with a water-soluble polymer, the core 50 can be eluted with water. For this reason, since the installation which elutes the core 50 can be simplified, an installation cost can be suppressed and cost reduction can be aimed at.
[0045]
In (c), the first separator 20 and the anode-side electrode diffusion layer 15 are taken out from the water tank 65. In the first separator 20 taken out, the fuel gas passage 26 is formed by the elution of the core 50 (shown in (b)).
The cooling water passage groove 21 of the first separator 20 can be formed by a cavity surface 63a (shown in (a)) of the fixed mold 61.
Thereby, the first separator 20 formed integrally with the anode side electrode diffusion layer 15 is obtained.
[0046]
In addition, the 2nd separator 40 integrally formed in the cathode side electrode diffusion layer 35 shown in FIG. 1 can also be obtained similarly to the 1st separator 2 by performing the process similar to the said FIGS. 4-7 sequentially. it can.
A state in which the first separator 20 formed integrally with the anode-side electrode diffusion layer 15 and the second separator 40 formed integrally with the cathode-side electrode diffusion layer 35 is combined is shown in the following figure.
[0047]
8 is a cross-sectional view taken along the line 8-8 in FIG. 1, and includes a first separator 20 formed integrally with the anode side electrode diffusion layer 15 and a second separator 40 formed integrally with the cathode side electrode diffusion layer 35. The state which match | combined with the cooling water channel | path formation surfaces 20a and 40a of each separator 20 and 40 is shown.
[0048]
By combining the first and second separators 20 and 40 with the respective cooling water passage forming surfaces 20a and 40a, the cooling water passage grooves 21... Of the first separator 20 and the cooling water passage grooves 41. ··· and the cooling water passage 30 can be formed.
[0049]
Further, by forming the first separator 20 integrally with the anode side electrode diffusion layer 15, the fuel gas passages 26 can be formed on the fuel gas passage forming surface 20b. Furthermore, by forming the second separator 40 integrally with the cathode side electrode diffusion layer 35, the oxidant gas passages 46 can be formed on the oxidant gas passage formation surface 40b.
[0050]
As described above, according to the first embodiment, the core 50 is formed of a water-soluble polymer, and the fuel gas passages 26 are formed in the first separator 20 with the core 50. Thus, the fuel gas passages 26... Can be opened by eluting the core 50 with the water 66 after the molding of the first separator 20.
[0051]
Similarly to the first separator 20, the second separator 40 was also formed with a core made of a water-soluble polymer, and an oxidant gas passage 46... Was formed in the second separator 40 with this core. Thus, the fuel gas passages 46 can be opened by eluting the core with the water 66 after the second separator 40 is molded.
Thus, since the cores in the first and second separators 20 and 40 can be eluted with the water 66, the fuel gas passages 26 ... and the oxidant gas passages are provided in the first and second separators 20 and 40. 46... Can be formed easily.
[0052]
Further, the first and second separators 20 and 40 were integrally formed with the anode side electrode diffusion layer 15 and the cathode electrode diffusion layer 35, respectively. Thereby, the electrical contact resistance between the first separator 20 and the anode-side electrode diffusion layer 15 can be suppressed, and the electrical contact resistance between the second separator 40 and the cathode electrode diffusion layer 35 can be reduced. Can be suppressed.
Thus, by suppressing the contact resistance, it is possible to reduce the resistance overvoltage and prevent the output of the fuel cell from decreasing.
[0053]
Next, the resistance overvoltage of the first embodiment will be described based on Table 1.
[0054]
[Table 1]

[0055]
In the first comparative example, the first separator and the anode-side electrode diffusion layer are not integrated, and the anode-side electrode diffusion layer is brought into contact with the first separator.
The first example is that of the first embodiment in which the first separator and the anode-side electrode diffusion layer are integrated.
[0056]
The resistance overvoltage between the first comparative example and the first example was measured under the following conditions.
That is, the temperature of the cell module is set to 80 ° C., and pure H is used as the anode gas (fuel gas).₂And air as a cathode gas (oxidant gas).
The anode-side fuel gas temperature was 80 ° C., the cathode-side oxidant gas temperature was 80 ° C., the anode-side fuel gas pressure was 50 kPa, and the cathode-side oxidant gas pressure was 100 kPa. Under this condition, the current density is 0.883 A / cm.²Current was passed.
[0057]
As a result, the resistance overvoltage of the first example was reduced by 0.014 V per cell module as compared with the resistance overvoltage of the first comparative example.
Therefore, as in the first example (first embodiment), it can be seen that by integrating the first separator and the anode-side electrode diffusion layer, it is possible to reduce the resistance overvoltage and prevent the output of the fuel cell from decreasing. .
[0058]
Next, 2nd Embodiment and 4th Embodiment are described. In the second and third embodiments, the same members as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
FIGS. 9A to 9C are process diagrams for explaining a method for manufacturing a fuel cell separator according to the present invention (second embodiment).
In (a), with the core molding die 76 clamped, the melted water-soluble polymer is filled into the cavity 76a of the core molding die 76 as shown by the arrow (3). After the water-soluble polymer is solidified to form the core 50, the movable mold 77 is raised as shown by an arrow.
[0059]
In (b), the core 50 is taken out from the cavity 76a of the core mold 76 that has been opened by raising the movable mold 77.
In (c), the core 50 is set on the fixed mold 61 of the mold 60, and after setting the core 50, the anode-side electrode diffusion layer 15 is placed on the core 50 as indicated by an arrow. Thus, after setting the core 50 and the anode side electrode diffusion layer 15 in the cavity 63, the movable mold 62 is lowered as shown by the arrow, and the mold 60 is clamped.
[0060]
Thereby, the state of FIG. 6B of the first embodiment is obtained. Hereinafter, the first separator 20 formed integrally with the anode side electrode diffusion layer 15 shown in FIG. 1 can be obtained by sequentially repeating the same steps as in the first embodiment.
Furthermore, the second separator 40 formed integrally with the cathode-side electrode diffusion layer 35 shown in FIG. 1 can be obtained by the same process as FIG.
[0061]
According to the second embodiment, the same effect as that of the first embodiment can be obtained.
Further, according to the method for manufacturing the fuel cell separator of the second embodiment, the core 50 can be formed separately from the anode-side electrode diffusion layer 15. Thereby, since the shaping | molding method of the core 50 can be suitably selected from any one of 1st, 2nd embodiment, the freedom degree of design can be raised.
[0062]
Next, a third embodiment will be described with reference to FIGS.
FIG. 10 shows an exploded perspective view of a fuel cell equipped with a fuel cell separator (third embodiment) according to the present invention.
The fuel cell 80 includes an anode side electrode 13 and a cathode side electrode 14 attached to the electrolyte membrane 12, and a separator (fuel cell separator) 82 is aligned with the anode side electrode 13 side via the anode side electrode diffusion layer 15. The cell module 81 is configured by combining the separator 82 with the side electrode 14 side through the cathode side electrode diffusion layer 35.
[0063]
11 is a cross-sectional view taken along line 11-11 of FIG.
The separator 82 is integrally formed with the anode-side electrode diffusion layer 15 on the fuel gas passage forming surface (one surface of both surfaces of the separator) 82a, so that the fuel gas passage (gas) is formed on the fuel gas passage forming surface 82a side. A large number of passages 84... Are formed.
[0064]
Further, the separator 82 is oxidized on the oxidant gas passage formation surface 82b side by integrally forming the cathode side electrode diffusion layer 35 on the oxidant gas passage formation surface (the other surface of both surfaces of the separator) 82b. A large number of agent gas passages (gas passages) 86 are formed.
Further, the separator 82 includes a plurality of cooling water passages 85 between the fuel gas passages 83 and the oxidant gas passages 84.
[0065]
As the resin constituting the separator 82, as in the first embodiment, as an example, a natural graphite, artificial graphite, ketjen black, acetylene black or the like is blended alone or in combination with a thermoplastic resin having acid resistance. A resin composition containing 60 to 90 wt% of the material is applicable.
[0066]
Examples of the thermoplastic resin having acid resistance include ethylene / vinyl acetate (vinyl acetate) copolymer, ethylene / ethyl acrylate copolymer, linear low density polyethylene, polyphenylene sulfide, and modified polyphenylene oxide. However, the present invention is not limited to this.
[0067]
Returning to FIG. 10, the fuel gas supply holes 91 a on the left side of the upper end of the separator 82 communicate with the fuel gas passages 83... (Shown in FIG. 11), and the fuel gas discharge hole 91 b on the right side of the lower end of the separator 82. Communicate.
Further, the oxidant gas passage 84 (see also FIG. 11) communicates with the oxidant gas supply hole 92a on the right side of the upper end of the separator 82, and the oxidant gas discharge hole 92b on the left side of the lower end of the separator 82. Communicate.
Furthermore, the cooling water passage 85... (Shown in FIG. 11) communicates with the cooling water supply hole 93 a at the center of the upper end of the separator 82, and communicates the cooling water discharge hole 93 b with the center of the lower end of the separator 82.
[0068]
That is, the fuel cell separator 82 of the third embodiment is formed by forming the cooling water passage 85... Between the fuel gas passage 83... And the oxidant gas passage 84. The other configurations are the same as those of the first embodiment, except that the first and second separators 20 and 40 of the embodiment are integrally formed, except for the first embodiment.
As described above, by integrally forming the first and second separators 20 and 40, the electrical contact resistance generated between the pair of separators 20 and 40 is eliminated, and the output reduction of the fuel cell is more preferably prevented. Can do.
[0069]
Next, a method for manufacturing a fuel cell separator will be described with reference to FIGS.
First, based on FIGS. 12 to 14, a water-soluble polymer is used to form a fuel gas passage 83, an oxidant gas passage 84, and a cooling water passage 85 (shown in FIG. 11). A process of forming the child 100 (shown in FIG. 14) will be described.
The core 100 includes a core for the first gas passage, a core for the second gas passage, and a core for the cooling water passage, and the core for the first gas passage, the core for the second gas passage, and the cooling water. The manufacturing process of the passage core will be described below.
[0070]
The core 100 is molded from a water-soluble polymer as in the first embodiment. Examples of the water-soluble polymer include, but are not limited to, polyacrylamide, polyacrylic acid, polymethacrylic acid, polyitaconic acid, and polyvinyl alcohol.
That is, any water-soluble polymer may be used as long as it can be used as a core and has water solubility.
[0071]
12 (a) to 12 (c) are first process diagrams for explaining a method (third embodiment) for producing a fuel cell separator according to the present invention, and a fuel gas passage 83 (shown in FIG. 11). An example of molding the first gas passage core will be described.
In (a), the anode side electrode diffusion layer 15 is set on the movable mold 87 with the core mold 86 opened, and then the movable mold 87 is lowered toward the fixed mold 88 as shown by the arrow. The mold 86 is clamped.
[0072]
In (b), the melted water-soluble polymer is filled into the cavity 86a of the core mold 86 as shown by the arrow (4). After the water-soluble polymer is solidified and the first gas passage core 101 is formed integrally with the anode-side electrode diffusion layer 15 (that is, integrated), the movable mold 87 is raised as shown by an arrow.
[0073]
In (c), the first gas passage core 101 formed integrally with the anode-side electrode diffusion layer 15 is taken out from the cavity 86a of the core mold 86 opened by raising the movable mold 87.
[0074]
On the other hand, the second gas passage core 105 (see FIG. 14) of the oxidant gas passage 84... (Shown in FIG. 11) is integrated with the cathode side electrode diffusion layer 35 in the same step as the step of FIG. Can be molded.
The first gas passage core 101 and anode side electrode diffusion layer 15 of the fuel gas passage 83... And the second gas passage core 105 and cathode side electrode diffusion layer 15 of the oxidant gas passage 84. 35 will be described in detail with reference to FIG.
[0075]
FIGS. 13 (a) and 13 (b) are second process diagrams for explaining a method for manufacturing a fuel cell separator (third embodiment) according to the present invention, in which a cooling water passage 85 (shown in FIG. 11). An example of forming the cooling water passage core will be described.
In (a), with the core mold 97 clamped, the melted water-soluble polymer is filled into the cavity 97a of the core mold 97 as shown by the arrow (5). After the water-soluble polymer is solidified and the cooling water passage core 111 is formed, the movable die 97 is raised as shown by an arrow.
[0076]
In (b), the cooling water passage core 111 is taken out from the cavity 97a of the core mold 96 opened by moving the movable mold 97 upward.
The cooling water passage core 111 of the formed cooling water passage 85... Will be described in detail with reference to FIG.
[0077]
FIG. 14 is a perspective view of cores (first and second gas passage cores and cooling water passage cores) used in the fuel cell separator manufacturing method (third embodiment) according to the present invention.
The anode-side electrode diffusion layer 15 includes a fuel gas supply hole 16a, a cooling water supply hole 18a, and an oxidant gas supply hole 17a on one end side, and a fuel gas discharge hole 16b and a cooling water discharge hole on the other end side. Part 18b and oxidant gas discharge hole 17b.
A first gas passage core 101 is formed integrally with the anode side electrode diffusion layer 15.
[0078]
That is, the first gas passage core 101 includes the fuel gas supply hole core 102 in the fuel gas supply hole portion 16a, and the fuel gas discharge hole core 103 in the fuel gas discharge hole portion 16b.
The fuel gas passage core 104 is integrally formed with the fuel gas supply hole core 102 and the fuel gas discharge hole core 103 to obtain the first gas passage core 101. The fuel gas passage core 104 is formed integrally with the anode side electrode diffusion layer 15.
Thereby, the anode side electrode diffusion layer 15 and the first gas passage core 101 can be integrated together.
[0079]
The cathode side electrode diffusion layer 35 includes a fuel gas supply hole 36a, a cooling water supply hole 38a, and an oxidant gas supply hole 37a on one end side, and a fuel gas discharge hole 36b and a cooling water discharge hole on the other end side. Part 38b and oxidant gas discharge hole 37b.
A second gas passage core 105 is formed integrally with the cathode side electrode diffusion layer 35.
[0080]
That is, the second gas passage core 105 includes the oxidant gas supply hole core 106 in the oxidant gas supply hole 37a and the oxidant gas discharge hole core 107 in the oxidant gas discharge hole 37b.
The oxidant gas passage core 108 is integrally formed with the oxidant gas supply hole core 106 and the oxidant gas discharge hole core 107 to obtain the second gas passage core 105. The oxidant gas passage core 108 is formed integrally with the cathode side electrode diffusion layer 35.
Thereby, the cathode side electrode diffusion layer 35 and the second gas passage core 105 can be integrated together.
[0081]
The cooling water passage core 111 disposed between the first gas passage core 101 and the second gas passage core 105 is integrally formed with a cooling water supply hole core 113 on one end side of the cooling water passage core 112. In addition, the cooling water discharge hole core 114 is integrally formed on the other end side.
The cooling water supply hole core 113 is fitted into the cooling water supply hole portions 18a and 38a of the anode side electrode diffusion layer 15 and the cathode side electrode diffusion layer 35, and the anode side electrode diffusion layer 15 and the cathode side electrode diffusion layer. The layers 35 are fitted into the respective cooling water discharge holes 18b and 38b.
[0082]
At the same time, the fuel gas supply hole core 102 and the fuel gas discharge hole core 103 on the anode side electrode diffusion layer 15 side are fitted into the fuel gas supply hole portion 36a and the fuel gas discharge hole portion 36b of the cathode side electrode diffusion layer 35, respectively. Include.
Further, the oxidant gas supply hole core 106 and the oxidant gas discharge hole core 107 on the cathode side electrode diffusion layer 35 side are connected to the oxidant gas supply hole part 17a and the oxidant gas discharge hole part of the anode side electrode diffusion layer 15. 17b is fitted in each.
[0083]
Accordingly, the lower ends 113 a and 114 a of the cooling water supply hole core 113 and the cooling water discharge hole core 114 are flush with the anode side electrode diffusion layer 15. The upper ends 113 and 114 b of the cooling water supply hole core 113 and the cooling water discharge hole core 114 are flush with the cathode side electrode diffusion layer 35.
[0084]
The upper ends 102 a and 103 a of the fuel gas supply hole core 102 and the fuel gas discharge hole core 103 are flush with the cathode side electrode diffusion layer 35.
Further, the lower ends 106 a and 107 a of the oxidant gas supply hole core 106 and the oxidant gas discharge hole core 107 are flush with the anode-side electrode diffusion layer 15.
[0085]
Next, a process of forming a separator will be described based on FIGS.
FIGS. 15A and 15B are third process diagrams for explaining the method for manufacturing a fuel cell separator according to the present invention (third embodiment).
In (a), the first gas passage core 101 and the anode-side electrode diffusion layer 15 are set on the stationary die 121 of the mold 120, and the cooling water passage core 111 is placed on the first gas passage core 101 with an arrow. Put it like this.
Next, after placing the second gas passage core 105 and the cathode side electrode diffusion layer 35 on the cooling water passage core 111 as shown by the arrow, the movable mold 122 is lowered as shown by the arrow and the mold 120 is clamped. To do.
[0086]
Here, as shown in FIG. 14, the second gas passage core 105 and the cathode-side electrode diffusion layer 35 are divided into an oxidant gas supply hole core 106 (shown in FIG. 14) and an oxidant gas discharge hole core 107. Can be supported on the cavity surface 123a.
Further, the cooling water passage core 111 can be supported on the cavity 123a surface by the cooling water supply hole core 113 (shown in FIG. 14) and the cooling water discharge hole core 114.
[0087]
As described above, the second gas passage core 105 is arranged in the cavity 123 by the oxidant gas supply hole core 106 and the oxidant gas discharge hole core 107, and the cooling water passage core 111 is supplied with cooling water. The hole core 113 and the cooling water discharge hole core 114 can be disposed in the cavity 123.
Therefore, it is possible to eliminate the need for a support member such as kelen that is normally required for disposing the second gas passage core 105 and the cooling water passage core 111 in the cavity 123.
[0088]
When a support member such as keren is provided, there is a possibility that a portion of the support member such as kelen remains as a gap in the separator after the cavity 123 is filled with resin and the separator is molded.
In that case, it is necessary to close the remaining gap with a sealing agent such as a silicone agent, but according to the third embodiment, this is not necessary.
[0089]
In (b), the mold 120 is clamped to place the first and second gas passage cores 101 and 105 and the cooling water passage core 111 in the cavity 123 of the mold 120. The anode side electrode diffusion layer 15 is disposed in the gap between the first gas passage core 101 and the cavity surface 123a, and the cathode side electrode diffusion layer 35 is disposed in the gap between the second gas passage core 105 and the cavity surface 123b. Deploy.
In this state, the cavity 123 is filled with molten resin as shown by the arrow (6).
[0090]
16 (a) to 16 (c) are fourth process diagrams illustrating a method for manufacturing a fuel cell separator according to the present invention (third embodiment).
In (a), the filled molten resin is solidified to make the separator 82 into the core 100 (first and second gas passage cores 101 and 105 and cooling water passage core 111), the anode-side electrode diffusion layer 15 and After integrally forming with the cathode electrode diffusion layer 35, the movable mold is raised and the mold 120 is opened.
After opening the mold, the separator 82, the core 100, the anode side electrode diffusion layer 15, and the cathode electrode diffusion layer 35 are taken out from the cavity 123.
[0091]
In (b), the separator 82, the core 100, the anode-side electrode diffusion layer 15, and the cathode electrode diffusion layer 35 are immersed in water 126 stored in the water tank 125.
As a result, the core 100 is dissolved from the separator 82 by being dissolved with the water 126.
Thus, the core 100 can be eluted with the water 126 by molding the core 100 with the water-soluble polymer. For this reason, since the facility which elutes the core 100 can be simplified, the facility cost can be suppressed and the cost can be reduced.
[0092]
In (c), the first and second gas passage cores 101 and 105 and the cooling water passage core 111 (shown in (b)) are eluted from the separator 82, so that the fuel gas passage 83 passes through the separator 82. ..., the cooling water passage 85 ... and the oxidant gas passage 84 ... can be opened.
In this state, the separator 82 integrally formed between the anode side electrode diffusion layer 15 and the cathode side electrode diffusion layer 35 is obtained by taking out the separator 82, the anode side electrode diffusion layer 15 and the cathode side electrode diffusion layer 35 from the water tank 125. obtain.
The separator 82 is shown in a state where the separator 82 shown in FIG. 11 is inverted.
[0093]
According to the third embodiment described above, the same effect as that of the first embodiment can be obtained. That is, according to the third embodiment, the core 100 is formed of a water-soluble polymer, and the fuel gas passages 83... And the oxidant gas passages 84.
Thus, the fuel gas passage 83... And the oxidant gas passage 84... Can be opened by eluting the core 100 with the water 126 after the separator 82 is formed.
[0094]
In this way, since the core 100 in the separator 82 can be eluted with the water 126, the fuel gas passages 83... And the oxidant gas passages 84.
[0095]
Further, the separator 82 was formed integrally with the anode side electrode diffusion layer 15 and the cathode electrode diffusion layer 35. Thereby, the electrical contact resistance between the separator 82 and the anode-side electrode diffusion layer 15 can be suppressed, and the electrical contact resistance between the separator 82 and the cathode electrode diffusion layer 35 can be suppressed. Therefore, it is possible to prevent a decrease in the output of the fuel cell.
[0096]
In addition, according to the third embodiment, the cooling water passage 85 is formed in the separator 82 using the core 100 of the water-soluble polymer. Since the cooling water passages 85 can be formed in the separator 82, it is not necessary to form a cooling water passage by overlapping a pair of separators as in the prior art.
[0097]
Thus, since a pair of separators conventionally required can be integrally formed, the electrical contact resistance generated between the pair of separators as in the prior art can be suppressed.
Thus, by suppressing the contact resistance, it is possible to reduce the resistance overvoltage and prevent the output of the fuel cell from decreasing.
[0098]
Next, the resistance overvoltage of the third embodiment will be described based on Table 2.
[0099]
[Table 2]

[0100]
In the second comparative example, the first separator and the second separator are not integrated, and the second separator is combined with the first separator.
The second example is that of the third embodiment in which separators are integrated.
[0101]
The resistance overvoltage between the second comparative example and the second example was measured under the following conditions.
That is, the temperature of the cell module is set to 80 ° C., and pure H is used as the anode gas (fuel gas).₂And air as a cathode gas (oxidant gas).
The anode-side fuel gas temperature was 80 ° C., the cathode-side oxidant gas temperature was 80 ° C., the anode-side fuel gas pressure was 50 kPa, and the cathode-side oxidant gas pressure was 100 kPa. Under this condition, the current density is 0.883 A / cm.²Current was passed.
[0102]
As a result, the resistance overvoltage of the second example was reduced by 0.027 V per cell module as compared with the resistance overvoltage of the second comparative example.
Therefore, it can be seen that by integrating the separator as in the second example (third embodiment), it is possible to reduce the resistance overvoltage and prevent the output of the fuel cell from decreasing.
[0103]
Next, a fourth embodiment will be described.
In the third embodiment, as shown in FIG. 14, the first gas passage core 101 is formed integrally with the anode side electrode diffusion layer 15 and is integrated with the second gas passage core 105 cathode side electrode diffusion layer 35. However, the present invention is not limited to this, and the first gas passage core 101 is formed separately from the anode side electrode diffusion layer 15 to form the second gas passage core 105 and the cathode side electrode diffusion layer 35. It is also possible to mold separately from the mold.
[0104]
In this case, first, the anode-side electrode diffusion layer 15 is disposed in the cavity 123 of the mold 120 shown in FIG. 15, and the first gas passage core 101 is placed on the anode-side electrode diffusion layer 15. After the cooling water passage core 111 is placed on the first gas passage core 101 and the second gas passage core 105 is placed on the cooling water passage core 111, the second gas passage core 105 is placed on the core 105. The cathode side electrode diffusion layer 35 is placed.
[0105]
By closing the mold 120 in this state, the first and second gas passage cores 101 and 105, the cooling water passage core 111 and the anode are formed as in FIG. 15B of the third embodiment. The side electrode diffusion layer 15 and the cathode side electrode diffusion layer 35 can be set in the cavity 123.
Therefore, also in 4th Embodiment, the effect similar to 3rd Embodiment can be acquired.
[0106]
In addition, according to the fuel cell separator manufacturing method of the fourth embodiment, the first gas passage core 101 can be formed separately from the anode-side electrode diffusion layer 15, and the second gas passage middle. The child 105 can be formed separately from the cathode side electrode diffusion layer 35.
Thereby, since the shaping | molding method of the core 101,105 for 1st, 2nd gas passages can be suitably selected from either one of 3rd, 4th embodiment, the freedom degree of design can be raised. it can.
[0107]
In the above-described embodiment, the solid polymer fuel cells 10 and 80 using the solid polymer electrolyte as the electrolyte membrane 12 have been described. However, the present invention is not limited to this and can be applied to other fuel cells. .
[0108]
In the first and second embodiments, the example in which the first and second separators 20 and 40 are molded by the injection molding method has been described. However, the present invention is not limited to this. For example, by the hot press molding method or the transfer molding method. It is also possible to mold.
The transfer molding apparatus is a method in which a molding material is put into a pot part separate from the cavity for one shot, and the molten material is transferred to the cavity by a plunger and molded.
[0109]
When the first and second separators 20 and 40 are molded by the hot press molding method, as a resin constituting the first and second separators 20 and 40, as an example, a thermosetting resin having acid resistance, A resin composition containing natural carbon, artificial graphite, ketjen black, acetylene black or the like alone or mixed and containing 60 to 90 wt% of a carbon material is applicable.
Examples of the thermosetting resin having acid resistance include phenol and vinyl ester, but are not limited thereto.
[0110]
【The invention's effect】
  The present invention exhibits the following effects by the above configuration.
  Claim 1, 2The gas passage can be formed by forming the core for forming the gas passage with a water-soluble polymer and eluting the core with water after molding the separator.
  Thus, since the core in a separator can be eluted with water, a gas passage can be easily formed in a separator and a separator can be manufactured easily.
[0111]
In addition, the separator is formed integrally with the electrode diffusion layer. Thereby, since the electrical contact resistance between a separator and an electrode diffusion layer can be suppressed, the output fall of a fuel cell can be prevented.
[0112]
  Claim3Can form the gas passage by forming the core for the gas passage for forming the gas passage with a water-soluble polymer and eluting the core for the gas passage with water after molding the separator.
  Thus, since the core for gas passages in a separator can be eluted with water, a gas passage can be easily formed in a separator and a separator can be manufactured easily.
[0113]
In addition, the separator is formed integrally with the electrode diffusion layer. Thereby, since the electrical contact resistance between a separator and an electrode diffusion layer can be suppressed, the output fall of a fuel cell can be prevented.
[0114]
Further, the cooling water passage core is formed of a water-soluble polymer, and the cooling water passage core is eluted with water after the separator is formed, so that the cooling water passage is formed in the separator. Since the cooling water passage can be formed in the separator, it is not necessary to form a cooling water passage by overlapping a pair of separators.
Thus, since it is not necessary to overlap a pair of separators, it is possible to eliminate an electrical contact resistance generated between the pair of separators as in the prior art, and to prevent a decrease in the output of the fuel cell.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a fuel cell equipped with a fuel cell separator according to the present invention (first embodiment).
2 is a sectional view taken along line 2-2 of FIG.
3 is a sectional view taken along line 3-3 in FIG.
FIG. 4 is a first process diagram illustrating a method for manufacturing a fuel cell separator according to the present invention (first embodiment);
FIG. 5 is a perspective view of a core used in the method for manufacturing a fuel cell separator according to the present invention (first embodiment).
FIG. 6 is a second process diagram for explaining a method for manufacturing a fuel cell separator according to the present invention (first embodiment);
FIG. 7 is a third step diagram for explaining a method of manufacturing a fuel cell separator according to the present invention (first embodiment).
8 is a cross-sectional view taken along line 8-8 in FIG.
FIG. 9 is a process diagram illustrating a method for manufacturing a fuel cell separator according to the present invention (second embodiment).
FIG. 10 is an exploded perspective view of a fuel cell equipped with a fuel cell separator (third embodiment) according to the present invention.
11 is a sectional view taken along line 11-11 in FIG.
FIG. 12 is a first process diagram illustrating a method for manufacturing a fuel cell separator according to the present invention (third embodiment).
FIG. 13 is a second process diagram illustrating a method for manufacturing a fuel cell separator according to the present invention (third embodiment).
FIG. 14 is a perspective view of a core (first and second gas passage cores and cooling water passage core) used in the fuel cell separator manufacturing method (third embodiment) according to the present invention;
FIG. 15 is a third step diagram for explaining a method of manufacturing a fuel cell separator according to the present invention (third embodiment).
FIG. 16 is a fourth process diagram for explaining the method for manufacturing a fuel cell separator according to the present invention (third embodiment);
FIG. 17 is an exploded perspective view showing a conventional fuel cell.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10,80 ... Fuel cell, 15 ... Anode side electrode diffusion layer (electrode diffusion layer), 20 ... 1st separator (separator for fuel cells), 20b ... Fuel gas passage formation surface (surface of separator), 26, 83 ... Fuel Gas passage (gas passage), 30, 85 ... cooling water passage, 35 ... cathode side electrode diffusion layer (electrode diffusion layer), 40 ... second separator (fuel cell separator), 40b ... oxidant gas passage formation surface, 46 , 84 ... Oxidant gas passage (gas passage), 50, 100 ... Core, 60, 120 ... Mold, 63, 123 ... Cavity, 63a, 63b, 123a, 123b ... Cavity surface, 66, 126 ... Water, 82 ... separator (fuel cell separator), 82b ... oxidant gas passage forming surface (the other of both sides of the separator), 101 ... first gas passage core, 105 ... second gas passage core, 11 ... cooling water passage core, 82a ... fuel gas passage forming surface (one side of the separator).

Claims (3)

Arranging an electrode diffusion layer in the cavity of the core mold;
Forming a core for forming a gas passage in the cavity integrally with the electrode diffusion layer with a water-soluble polymer;
Removing the integrally formed core and electrode diffusion layer from the core mold and placing them in the cavity of the mold; and
Filling the mold cavity with molten resin;
Removing the solidified separator of the molten resin from the cavity of the mold after integrally forming the core and the electrode diffusion layer;
A method for producing a fuel cell separator comprising the step of dissolving the core with water and eluting from the separator to form the gas passage by the separator and the electrode diffusion layer. Forming a core for forming a gas passage with a water-soluble polymer;
Placing the core in the cavity of the mold , and placing an electrode diffusion layer in the core in the cavity ;
Filling the cavity with molten resin;
A step of taking out the separator to coagulate the molten resin from said core and said electrode diffusion layer and the cavity was formed integrally,
By eluting from the separator by dissolving the core in water, the separator and method for producing a fuel cell separator comprising a step of forming the gas passage in the electrode diffusion layer. Arranging the electrode diffusion layer in the cavity of the core forming die for the gas passage;
In the cavity, forming a gas passage core for forming a gas passage integrally with the electrode diffusion layer with a water-soluble polymer;
Forming a cooling water passage core for forming the cooling water passage in the cavity of the cooling water passage core mold with a water-soluble polymer ; and
The integrally formed gas passage core and electrode diffusion layer are taken out from the gas passage core mold and placed in a cavity of the mold, and the cooling is taken out from the cooling water path core mold. Disposing a water passage core in the cavity of the mold at a predetermined interval from the gas passage core;
Filling the mold cavity with molten resin;
A step of taking out the separator to coagulate the molten resin, the gas passage core, from the cooling water passage core and the electrode diffusion layer and the mold after forming integrally cavity,
By eluting from the separator the gas passage core and the cooling water passage core was dissolved respectively in water, to form a gas passage in the separator and the electrode diffusion layer, the cooling water in the separator The manufacturing method of the separator for fuel cells which consists of the process of forming a channel | path.

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