JP6170868B2

JP6170868B2 - Fuel cell

Info

Publication number: JP6170868B2
Application number: JP2014087053A
Authority: JP
Inventors: 尚紀山野; 賢小山; 祐樹濱
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2014-04-21
Filing date: 2014-04-21
Publication date: 2017-07-26
Anticipated expiration: 2034-04-21
Also published as: JP2015207438A

Description

本発明は、電解質膜・電極構造体の外周を周回して樹脂枠部材が設けられる樹脂枠付きＭＥＡと、前記樹脂枠付きＭＥＡの両側に積層される第１のセパレータ及び第２のセパレータとを備える燃料電池に関する。 The present invention includes an MEA with a resin frame in which a resin frame member is provided around the outer periphery of the electrolyte membrane / electrode structure, and a first separator and a second separator laminated on both sides of the MEA with a resin frame. The present invention relates to a fuel cell provided.

一般的に、固体高分子型燃料電池は、高分子イオン交換膜からなる固体高分子電解質膜を採用している。燃料電池は、固体高分子電解質膜の一方側にアノード電極が、前記固体高分子電解質膜の他方側にカソード電極が、それぞれ設けられた電解質膜・電極構造体（ＭＥＡ）を備えている。電解質膜・電極構造体は、セパレータ（バイポーラ板）によって挟持されることにより、燃料電池が構成されている。この燃料電池は、所定の数だけ積層することにより、例えば、車載用燃料電池スタックとして燃料電池電気自動車に搭載されている。 In general, a polymer electrolyte fuel cell employs a polymer electrolyte membrane made of a polymer ion exchange membrane. The fuel cell includes an electrolyte membrane / electrode structure (MEA) in which an anode electrode is provided on one side of the solid polymer electrolyte membrane and a cathode electrode is provided on the other side of the solid polymer electrolyte membrane. The electrolyte membrane / electrode structure is sandwiched between separators (bipolar plates) to constitute a fuel cell. This fuel cell is mounted on a fuel cell electric vehicle as a vehicle fuel cell stack, for example, by stacking a predetermined number.

電解質膜・電極構造体では、一方のガス拡散層が固体高分子電解質膜よりも小さな平面寸法に設定されるとともに、他方のガス拡散層が前記固体高分子電解質膜と同一の平面寸法に設定される、所謂、段差ＭＥＡを構成する場合がある。その際、比較的高価な固体高分子電解質膜の使用量を削減させるとともに、薄膜状で強度が低い前記固体高分子電解質膜を保護するために、種々の提案がなされている。 In the electrolyte membrane / electrode structure, one gas diffusion layer is set to a plane size smaller than that of the solid polymer electrolyte membrane, and the other gas diffusion layer is set to the same plane size as the solid polymer electrolyte membrane. In other words, a so-called step MEA may be formed. At that time, various proposals have been made to reduce the amount of the relatively expensive solid polymer electrolyte membrane used and to protect the solid polymer electrolyte membrane having a thin film shape and low strength.

例えば、特許文献１に開示されている燃料電池セルは、図６に示すように、膜・電極構造体１と、前記膜・電極構造体１を挟持する第１セパレータ２ａ及び第２セパレータ２ｂとを備え、これらが複数積層されている。第１セパレータ２ａには、燃料ガス流路溝３ａが形成される一方、第２セパレータ２ｂには、酸化剤ガス流路溝３ｂが形成されている。 For example, as shown in FIG. 6, the fuel cell disclosed in Patent Document 1 includes a membrane / electrode structure 1, and a first separator 2 a and a second separator 2 b that sandwich the membrane / electrode structure 1. A plurality of these are stacked. The first separator 2a is formed with a fuel gas channel groove 3a, while the second separator 2b is formed with an oxidant gas channel groove 3b.

膜・電極構造体１は、固体高分子電解質膜４と、前記固体高分子電解質膜４を挟んで配設されるアノード電極５ａ及びカソード電極５ｂとを有している。固体高分子電解質膜４の外周部分は、アノード電極５ａ及びカソード電極５ｂから若干はみ出している。このはみ出した部分の外周側には、固体高分子電解質膜４より平面寸法の大きい額状の第１シール部材６が一体的に設けられている。 The membrane / electrode structure 1 includes a solid polymer electrolyte membrane 4, and an anode electrode 5a and a cathode electrode 5b disposed with the solid polymer electrolyte membrane 4 interposed therebetween. The outer peripheral portion of the solid polymer electrolyte membrane 4 slightly protrudes from the anode electrode 5a and the cathode electrode 5b. A frame-shaped first seal member 6 having a larger planar dimension than that of the solid polymer electrolyte membrane 4 is integrally provided on the outer peripheral side of the protruding portion.

第１シール部材６の表面と、第２シール部材７とが密着されることにより、膜・電極構造体１を外部に対してシールしている。第１シール部材６及び第２シール部材７の外側であって、第１セパレータ２ａ及び第２セパレータ２ｂ間に第３シール部材８が設けられ、燃料電池セルを形成している。 When the surface of the first seal member 6 and the second seal member 7 are in close contact, the membrane / electrode structure 1 is sealed to the outside. A third seal member 8 is provided outside the first seal member 6 and the second seal member 7 and between the first separator 2a and the second separator 2b to form a fuel cell.

特開２００３−３１２３７号公報Japanese Patent Laid-Open No. 2003-31237

ところで、上記の燃料電池セルでは、膜・電極構造体１の外周を周回して第３シール部材８が設けられるとともに、前記第３シール部材８は、断面円形状を有している。このため、第３シール部材８では、第１セパレータ２ａ及び第２セパレータ２ｂに接触するシール幅が狭小になり易い。従って、第３シール部材８と第１セパレータ２ａ及び第２セパレータ２ｂとの間から、反応ガス、特に燃料ガスが外部に透過するおそれがある。 By the way, in the fuel cell described above, the third seal member 8 is provided around the outer periphery of the membrane / electrode structure 1, and the third seal member 8 has a circular cross section. For this reason, in the 3rd seal member 8, the seal width which contacts the 1st separator 2a and the 2nd separator 2b tends to become narrow. Therefore, there is a possibility that the reaction gas, in particular, the fuel gas may permeate outside from between the third seal member 8 and the first separator 2a and the second separator 2b.

本発明は、この種の問題を解決するものであり、簡単な構成で、反応ガスが外部に透過することを可及的に抑制することが可能な燃料電池を提供することを目的とする。 The present invention solves this type of problem, and an object thereof is to provide a fuel cell capable of suppressing the permeation of a reaction gas to the outside as much as possible with a simple configuration.

本発明に係る燃料電池は、電解質膜の両側に電極を配設した電解質膜・電極構造体を有し、前記電解質膜・電極構造体の外周を周回して樹脂枠部材が設けられる樹脂枠付きＭＥＡを備えている。樹脂枠付きＭＥＡの両側には、前記樹脂枠付きＭＥＡの外形寸法よりも大きな外形寸法を有する第１のセパレータ及び第２のセパレータが積層されている。第１のセパレータ及び第２のセパレータには、積層方向に貫通してそれぞれ燃料ガス、酸化剤ガス又は冷却媒体を流通させる複数の流体連通孔が形成されている。 A fuel cell according to the present invention has an electrolyte membrane / electrode structure in which electrodes are arranged on both sides of an electrolyte membrane, and has a resin frame around which an outer periphery of the electrolyte membrane / electrode structure is provided. MEA is provided. A first separator and a second separator having outer dimensions larger than the outer dimensions of the MEA with resin frame are stacked on both sides of the MEA with resin frame. The first separator and the second separator are formed with a plurality of fluid communication holes penetrating in the stacking direction and allowing the fuel gas, the oxidant gas, or the cooling medium to flow therethrough.

第１のセパレータには、積層方向に沿って樹脂枠部材の外周縁部に重なり合う位置に、断面矩形状の内側シール部材が配置されている。第２のセパレータには、樹脂枠部材の外方に且つ積層方向に沿って第１のセパレータに重なり合う位置に、断面矩形状の外側シール部材が配置されている。 In the first separator, an inner seal member having a rectangular cross section is disposed at a position overlapping the outer peripheral edge of the resin frame member along the stacking direction. In the second separator, an outer seal member having a rectangular cross section is disposed outside the resin frame member and at a position overlapping the first separator along the stacking direction.

そして、外側シール部材は、内側シール部材の外周及び流体連通孔を囲繞するとともに、前記外側シール部材のシール幅は、前記内側シール部材のシール幅よりも大きな寸法に設定されている。 The outer seal member surrounds the outer periphery of the inner seal member and the fluid communication hole, and the seal width of the outer seal member is set to be larger than the seal width of the inner seal member.

また、第１のセパレータの外周には、外側シール部材の外方に位置して第１外周シールが設けられるとともに、第２のセパレータの外周には、前記外側シール部材の外方に位置して第２外周シールが設けられることが好ましい。その際、第１外周シールと第２外周シールとは、互いに積層方向に沿って重なり合うことが好ましい。 In addition, a first outer peripheral seal is provided on the outer periphery of the first separator so as to be located outside the outer seal member, and an outer periphery of the second separator is positioned on the outer side of the outer seal member. A second outer peripheral seal is preferably provided. In that case, it is preferable that a 1st outer periphery seal | sticker and a 2nd outer periphery seal | sticker mutually overlap along a lamination direction.

さらに、本発明では、第１のセパレータ及び第２のセパレータのいずれか一方には、積層方向に沿って樹脂枠部材の外周縁部に重なり合う位置に配置される断面矩形状の内側シール部材が設けられている。他方には、流体連通孔を囲繞して配置される断面矩形状の外側シール部材が設けられている。そして、外側シール部材のシール幅は、内側シール部材のシール幅よりも大きな寸法に設定されている。 Furthermore, in the present invention, either one of the first separator and the second separator is provided with an inner seal member having a rectangular cross section disposed at a position overlapping the outer peripheral edge of the resin frame member along the stacking direction. It has been. On the other side , an outer seal member having a rectangular cross section is provided so as to surround the fluid communication hole. The seal width of the outer seal member is set to be larger than the seal width of the inner seal member.

さらにまた、本発明に係る燃料電池は、電解質膜の両側に電極を配設した電解質膜・電極構造体を備えている。電解質膜・電極構造体の両側には、前記電解質膜・電極構造体の外形寸法よりも大きな外形寸法を有し、該電解質膜・電極構造体の両側に積層される第１のセパレータ及び第２のセパレータが積層されている。第１のセパレータ及び第２のセパレータには、積層方向に貫通してそれぞれ燃料ガス、酸化剤ガス又は冷却媒体を流通させる複数の流体連通孔が形成されている。 Furthermore, the fuel cell according to the present invention includes an electrolyte membrane / electrode structure in which electrodes are disposed on both sides of the electrolyte membrane. A first separator and a second separator that have outer dimensions larger than the outer dimensions of the electrolyte membrane / electrode structure on both sides of the electrolyte membrane / electrode structure, and are stacked on both sides of the electrolyte membrane / electrode structure. The separators are stacked. The first separator and the second separator are formed with a plurality of fluid communication holes penetrating in the stacking direction and allowing the fuel gas, the oxidant gas, or the cooling medium to flow therethrough.

第１のセパレータには、積層方向に沿って電解質膜・電極構造体の外周縁部に重なり合う位置に、断面矩形状の内側シール部材が配置されている。第２のセパレータには、電解質膜・電極構造体の外方に且つ積層方向に沿って第１のセパレータに重なり合う位置であって電解質膜・電極構造体に重なり合わない位置に、断面矩形状の外側シール部材が配置されている。 In the first separator, an inner seal member having a rectangular cross section is disposed at a position overlapping the outer peripheral edge of the electrolyte membrane / electrode structure along the stacking direction. The second separator has a rectangular cross-section at a position that overlaps the first separator along the stacking direction outside the electrolyte membrane / electrode structure and does not overlap the electrolyte membrane / electrode structure . An outer seal member is disposed.

本発明によれば、外側シール部材は、内側シール部材の外周及び流体連通孔を囲繞するとともに、前記外側シール部材のシール幅は、前記内側シール部材のシール幅よりも大きな寸法に設定されている。このため、簡単な構成で、反応ガスが外部に透過することを可及的に抑制することが可能になる。 According to the present invention, the outer seal member surrounds the outer periphery of the inner seal member and the fluid communication hole, and the seal width of the outer seal member is set to be larger than the seal width of the inner seal member. . For this reason, it becomes possible to suppress as much as possible that the reaction gas permeates to the outside with a simple configuration.

本発明の実施形態に係る燃料電池を構成する発電ユニットの要部分解斜視説明図である。It is a principal part disassembled perspective explanatory drawing of the electric power generation unit which comprises the fuel cell which concerns on embodiment of this invention. 前記燃料電池の、図１中、ＩＩ−ＩＩ線断面説明図である。FIG. 2 is a sectional view of the fuel cell taken along line II-II in FIG. 1. 前記発電ユニットの要部拡大断面図である。It is a principal part expanded sectional view of the said electric power generation unit. 前記発電ユニットを構成する第１金属セパレータの正面説明図である。It is front explanatory drawing of the 1st metal separator which comprises the said electric power generation unit. 前記発電ユニットを構成する第２金属セパレータの正面説明図である。It is front explanatory drawing of the 2nd metal separator which comprises the said electric power generation unit. 特許文献１に開示されている燃料電池セルの要部断面説明図である。FIG. 4 is a cross-sectional explanatory view of a main part of a fuel battery cell disclosed in Patent Document 1.

図１〜図３に示すように、本発明の第１の実施形態に係る燃料電池１０は、矢印Ａ方向（例えば、水平方向）に複数の発電ユニット１２が積層されることにより、スタックを構成する。このスタックは、例えば、車載用燃料電池スタックとして燃料電池電気自動車（図示せず）に搭載される。 As shown in FIGS. 1 to 3, the fuel cell 10 according to the first embodiment of the present invention forms a stack by stacking a plurality of power generation units 12 in the direction of arrow A (for example, the horizontal direction). To do. This stack is mounted on, for example, a fuel cell electric vehicle (not shown) as an in-vehicle fuel cell stack.

発電ユニット１２は、第１金属セパレータ１４、第１樹脂枠付きＭＥＡ１６ａ、第２金属セパレータ１８、第２樹脂枠付きＭＥＡ１６ｂ及び第３金属セパレータ２０を積層する。 The power generation unit 12 includes a first metal separator 14, an MEA 16 a with a first resin frame, a second metal separator 18, an MEA 16 b with a second resin frame, and a third metal separator 20.

第１金属セパレータ１４、第２金属セパレータ１８及び第３金属セパレータ２０は、例えば、鋼板、ステンレス鋼板、アルミニウム板、めっき処理鋼板等により構成される。第１金属セパレータ１４、第２金属セパレータ１８及び第３金属セパレータ２０は、平面が矩形状を有するとともに、金属製薄板を波形状にプレス加工することにより、断面凹凸形状に成形される。なお、第１金属セパレータ１４、第２金属セパレータ１８及び第３金属セパレータ２０に代えて、例えば、カーボンセパレータを用いてもよい。 The first metal separator 14, the second metal separator 18, and the third metal separator 20 are made of, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or the like. The first metal separator 14, the second metal separator 18, and the third metal separator 20 have a rectangular planar shape, and are formed into a concavo-convex shape by pressing a metal thin plate into a wave shape. Instead of the first metal separator 14, the second metal separator 18, and the third metal separator 20, for example, a carbon separator may be used.

図１に示すように、発電ユニット１２の長辺方向（矢印Ｂ方向）の一端縁部には、矢印Ａ方向（積層方向）に互いに連通して、酸化剤ガス入口連通孔２２ａ及び燃料ガス出口連通孔２４ｂが設けられる。具体的には、酸化剤ガス入口連通孔２２ａ及び燃料ガス出口連通孔２４ｂは、第１金属セパレータ１４、第２金属セパレータ１８及び第３金属セパレータ２０の長辺方向の一端縁部に設けられる。酸化剤ガス入口連通孔２２ａは、酸化剤ガス、例えば、酸素含有ガスを供給する一方、燃料ガス出口連通孔２４ｂは、燃料ガス、例えば、水素含有ガスを排出する。 As shown in FIG. 1, the oxidant gas inlet communication hole 22a and the fuel gas outlet are communicated with one end edge of the power generation unit 12 in the long side direction (arrow B direction) in the arrow A direction (stacking direction). A communication hole 24b is provided. Specifically, the oxidant gas inlet communication hole 22 a and the fuel gas outlet communication hole 24 b are provided at one end edge in the long side direction of the first metal separator 14, the second metal separator 18, and the third metal separator 20. The oxidant gas inlet communication hole 22a supplies an oxidant gas, for example, an oxygen-containing gas, while the fuel gas outlet communication hole 24b discharges a fuel gas, for example, a hydrogen-containing gas.

発電ユニット１２の長辺方向（矢印Ｂ方向）の他端縁部には、矢印Ａ方向に互いに連通して、燃料ガスを供給するための燃料ガス入口連通孔２４ａ、及び酸化剤ガスを排出するための酸化剤ガス出口連通孔２２ｂが設けられる。 The other end edge of the power generation unit 12 in the long side direction (arrow B direction) communicates with each other in the arrow A direction, and discharges the fuel gas inlet communication hole 24a for supplying fuel gas and the oxidant gas. For this purpose, an oxidant gas outlet communication hole 22b is provided.

発電ユニット１２の短辺方向（矢印Ｃ方向）の両端縁部には、酸化剤ガス入口連通孔２２ａ側に、矢印Ａ方向に互いに連通して冷却媒体を供給するための一対の冷却媒体入口連通孔２５ａが設けられる。発電ユニット１２の短辺方向の両端縁部には、燃料ガス入口連通孔２４ａ側に、冷却媒体を排出するための一対の冷却媒体出口連通孔２５ｂが設けられる。 A pair of cooling medium inlets for communicating with each other in the direction of arrow A and supplying the cooling medium to the oxidant gas inlet communication hole 22a side at both ends of the short side direction (arrow C direction) of the power generation unit 12 A hole 25a is provided. A pair of cooling medium outlet communication holes 25b for discharging the cooling medium are provided on both ends of the power generation unit 12 in the short side direction on the fuel gas inlet communication hole 24a side.

図４に示すように、第１金属セパレータ１４の第１樹脂枠付きＭＥＡ１６ａに向かう面１４ａには、酸化剤ガス入口連通孔２２ａと酸化剤ガス出口連通孔２２ｂとに連通する第１酸化剤ガス流路２６が形成される。第１酸化剤ガス流路２６は、矢印Ｂ方向に延在する複数の波状流路溝部（直線状流路溝部でもよい）２６ａを有する。 As shown in FIG. 4, the first oxidant gas communicating with the oxidant gas inlet communication hole 22a and the oxidant gas outlet communication hole 22b is formed on the surface 14a of the first metal separator 14 facing the MEA 16a with the first resin frame. A flow path 26 is formed. The first oxidizing gas channel 26 has a plurality of wave-like channel grooves (or linear channel grooves) 26a extending in the direction of arrow B.

第１酸化剤ガス流路２６の入口側と酸化剤ガス入口連通孔２２ａとの間には、複数本の入口連結溝３０ａが形成される。第１酸化剤ガス流路２６の出口側と酸化剤ガス出口連通孔２２ｂとの間には、複数本の出口連結溝３０ｂが形成される。 A plurality of inlet connection grooves 30a are formed between the inlet side of the first oxidant gas flow channel 26 and the oxidant gas inlet communication hole 22a. A plurality of outlet connection grooves 30b are formed between the outlet side of the first oxidant gas flow channel 26 and the oxidant gas outlet communication hole 22b.

図１に示すように、第１金属セパレータ１４の面１４ｂには、一対の冷却媒体入口連通孔２５ａと一対の冷却媒体出口連通孔２５ｂとに連通する冷却媒体流路３２の一部が形成される。 As shown in FIG. 1, a part of the cooling medium flow path 32 communicating with the pair of cooling medium inlet communication holes 25 a and the pair of cooling medium outlet communication holes 25 b is formed on the surface 14 b of the first metal separator 14. The

第２金属セパレータ１８の第１樹脂枠付きＭＥＡ１６ａに向かう面１８ａには、燃料ガス入口連通孔２４ａと燃料ガス出口連通孔２４ｂとに連通する第１燃料ガス流路３４が形成される。第１燃料ガス流路３４は、矢印Ｂ方向に延在する複数の波状流路溝部（直線状流路溝部でもよい）３４ａを有する。 A first fuel gas passage 34 communicating with the fuel gas inlet communication hole 24a and the fuel gas outlet communication hole 24b is formed on the surface 18a of the second metal separator 18 facing the MEA 16a with the first resin frame. The first fuel gas channel 34 has a plurality of wave-like channel grooves (or linear channel grooves) 34 a extending in the direction of arrow B.

燃料ガス入口連通孔２４ａの近傍には、前記燃料ガス入口連通孔２４ａと第１燃料ガス流路３４とを連通する複数の供給流路溝部３６ａが形成される。複数の供給流路溝部３６ａは、蓋体３７ａにより覆われる。燃料ガス出口連通孔２４ｂの近傍には、前記燃料ガス出口連通孔２４ｂと第１燃料ガス流路３４とを連通する複数の排出流路溝部３６ｂが形成される。複数の排出流路溝部３６ｂは、蓋体３７ｂにより覆われる。 In the vicinity of the fuel gas inlet communication hole 24a, a plurality of supply flow channel grooves 36a that connect the fuel gas inlet communication hole 24a and the first fuel gas flow channel 34 are formed. The plurality of supply flow channel grooves 36a are covered with a lid body 37a. In the vicinity of the fuel gas outlet communication hole 24b, a plurality of discharge flow channel grooves 36b that connect the fuel gas outlet communication hole 24b and the first fuel gas flow channel 34 are formed. The plurality of discharge channel grooves 36b are covered with a lid body 37b.

図５に示すように、第２金属セパレータ１８の第２樹脂枠付きＭＥＡ１６ｂに向かう面１８ｂには、酸化剤ガス入口連通孔２２ａと酸化剤ガス出口連通孔２２ｂとに連通する第２酸化剤ガス流路３８が形成される。第２酸化剤ガス流路３８は、矢印Ｂ方向に延在する複数の波状流路溝部（直線状流路溝部でもよい）３８ａを有する。 As shown in FIG. 5, the second oxidant gas communicating with the oxidant gas inlet communication hole 22a and the oxidant gas outlet communication hole 22b is formed on the surface 18b of the second metal separator 18 facing the MEA 16b with the second resin frame. A flow path 38 is formed. The second oxidant gas channel 38 has a plurality of wave-like channel grooves (or linear channel grooves) 38a extending in the arrow B direction.

第２酸化剤ガス流路３８の入口側と酸化剤ガス入口連通孔２２ａとの間には、複数本の入口連結溝４０ａが形成される。第２酸化剤ガス流路３８の出口側と酸化剤ガス出口連通孔２２ｂとの間には、複数本の出口連結溝４０ｂが形成される。 A plurality of inlet connection grooves 40a are formed between the inlet side of the second oxidant gas flow path 38 and the oxidant gas inlet communication hole 22a. A plurality of outlet connection grooves 40b are formed between the outlet side of the second oxidant gas passage 38 and the oxidant gas outlet communication hole 22b.

図１に示すように、第３金属セパレータ２０の第２樹脂枠付きＭＥＡ１６ｂに向かう面２０ａには、燃料ガス入口連通孔２４ａと燃料ガス出口連通孔２４ｂとに連通する第２燃料ガス流路４２が形成される。第２燃料ガス流路４２は、矢印Ｂ方向に延在する複数の波状流路溝部（直線状流路溝部でもよい）４２ａを有する。 As shown in FIG. 1, a second fuel gas flow path 42 communicating with the fuel gas inlet communication hole 24a and the fuel gas outlet communication hole 24b is formed on the surface 20a of the third metal separator 20 facing the MEA 16b with the second resin frame. Is formed. The second fuel gas channel 42 has a plurality of wave-like channel grooves (or linear channel grooves) 42 a extending in the direction of arrow B.

燃料ガス入口連通孔２４ａの近傍には、前記燃料ガス入口連通孔２４ａと第２燃料ガス流路４２とを連通する複数の供給流路溝部４４ａが形成される。複数の供給流路溝部４４ａは、蓋体４５ａにより覆われる。燃料ガス出口連通孔２４ｂの近傍には、前記燃料ガス出口連通孔２４ｂと第２燃料ガス流路４２とを連通する複数の排出流路溝部４４ｂが形成される。複数の排出流路溝部４４ｂは、蓋体４５ｂにより覆われる。 In the vicinity of the fuel gas inlet communication hole 24a, a plurality of supply flow channel grooves 44a that connect the fuel gas inlet communication hole 24a and the second fuel gas flow channel 42 are formed. The plurality of supply flow channel grooves 44a are covered with a lid body 45a. In the vicinity of the fuel gas outlet communication hole 24b, a plurality of discharge flow channel grooves 44b that connect the fuel gas outlet communication hole 24b and the second fuel gas flow channel 42 are formed. The plurality of discharge channel grooves 44b are covered with a lid 45b.

第３金属セパレータ２０の面２０ｂには、第２燃料ガス流路４２の裏面形状である冷却媒体流路３２の一部が形成される。第３金属セパレータ２０の面２０ｂには、前記第３金属セパレータ２０に隣接する第１金属セパレータ１４の面１４ｂが積層されることにより、冷却媒体流路３２が一体に設けられる。 A part of the coolant flow path 32 that is the back surface shape of the second fuel gas flow path 42 is formed on the surface 20 b of the third metal separator 20. A cooling medium flow path 32 is integrally provided on the surface 20 b of the third metal separator 20 by laminating the surface 14 b of the first metal separator 14 adjacent to the third metal separator 20.

第１金属セパレータ１４の面１４ａ、１４ｂには、この第１金属セパレータ１４の外周端縁部を周回して第１シール部材４６が一体成形される。第２金属セパレータ１８の面１８ａ、１８ｂには、この第２金属セパレータ１８の外周端縁部を周回して第２シール部材４８が一体成形される。第３金属セパレータ２０の面２０ａ、２０ｂには、この第３金属セパレータ２０の外周端縁部を周回して第３シール部材５０が一体成形される。 A first seal member 46 is integrally formed on the surfaces 14 a and 14 b of the first metal separator 14 around the outer peripheral edge of the first metal separator 14. A second seal member 48 is integrally formed on the surfaces 18 a and 18 b of the second metal separator 18 around the outer peripheral edge of the second metal separator 18. A third seal member 50 is integrally formed on the surfaces 20 a and 20 b of the third metal separator 20 around the outer peripheral edge of the third metal separator 20.

第１シール部材４６、第２シール部材４８及び第３シール部材５０としては、例えば、ＥＰＤＭ、ＮＢＲ、フッ素ゴム、シリコーンゴム、フロロシリコーンゴム、ブチルゴム、天然ゴム、スチレンゴム、クロロプレーン又はアクリルゴム等のシール材、クッション材、あるいはパッキン材等の弾性を有するシール材が用いられる。 Examples of the first seal member 46, the second seal member 48, and the third seal member 50 include EPDM, NBR, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene, or acrylic rubber. A sealing material having elasticity such as a sealing material, a cushioning material, or a packing material is used.

図１〜図３に示すように、第１シール部材４６は、均一の厚さを有して第１金属セパレータ１４の面１４ａ、１４ｂの面方向に沿って延在する平面シール部４６ａを有する。第１金属セパレータ１４の面１４ａにおいて、平面シール部４６ａからは、外側シール部材（凸状シール部材）４６ｂが厚さ方向に一体に膨出形成される。外側シール部材４６ｂは、第１樹脂枠付きＭＥＡ１６ａの外方に且つ積層方向に沿って第２金属セパレータ１８に重なり合う位置に設けられるとともに、積層した後に略断面矩形状を有する。外側シール部材４６ｂは、積層前に先端に大きなＲがあってもよく、また、シール成形時の小さな抜き勾配を有する場合がある。 As shown in FIGS. 1 to 3, the first seal member 46 has a flat seal portion 46 a having a uniform thickness and extending along the surface direction of the surfaces 14 a and 14 b of the first metal separator 14. . On the surface 14a of the first metal separator 14, an outer seal member (convex seal member) 46b is integrally bulged and formed in the thickness direction from the flat seal portion 46a. The outer seal member 46b is provided outside the first resin frame-attached MEA 16a and at a position overlapping the second metal separator 18 along the stacking direction, and has a substantially cross-sectional rectangular shape after being stacked. The outer seal member 46b may have a large R at the tip before lamination, and may have a small draft at the time of seal molding.

平面シール部４６ａと外側シール部材４６ｂとの境界部位には、成形時の抜き勾配であるＲ形状部が設けられる。なお、以下に説明する平面シール部とシール部材（凸状シール部材）との各境界部位には、同様にＲ形状部が設けられる（図３参照）。 An R-shaped portion that is a draft at the time of molding is provided at a boundary portion between the flat seal portion 46a and the outer seal member 46b. In addition, an R-shaped portion is similarly provided at each boundary portion between the flat seal portion and the seal member (convex seal member) described below (see FIG. 3).

第１金属セパレータ１４の面１４ｂにおいて、平面シール部４６ａからは、積層方向に沿って後述する第１樹脂枠部材５８及び第２樹脂枠部材６０の外周縁部に重なり合う位置に、内側シール部材４６ｃが厚さ方向に一体に膨出形成される。 On the surface 14 b of the first metal separator 14, the inner seal member 46 c extends from the flat seal portion 46 a to a position overlapping the outer peripheral edge portions of the first resin frame member 58 and the second resin frame member 60 described later along the stacking direction. Are bulged and formed integrally in the thickness direction.

図１に示すように、内側シール部材４６ｃは、積層した後に略断面矩形状を有し、冷却媒体入口連通孔２５ａ及び冷却媒体出口連通孔２５ｂと冷却媒体流路３２とを周回する。内側シール部材４６ｃは、積層前に先端に大きなＲがあってもよく、また、シール成形時の小さな抜き勾配を有する場合がある。面１４ｂには、酸化剤ガス入口連通孔２２ａ、酸化剤ガス出口連通孔２２ｂ、燃料ガス入口連通孔２４ａ及び燃料ガス出口連通孔２４ｂを囲繞する外側シール部材４６ｄが設けられる。 As shown in FIG. 1, the inner seal member 46 c has a substantially cross-sectional rectangular shape after being stacked, and goes around the cooling medium inlet communication hole 25 a, the cooling medium outlet communication hole 25 b, and the cooling medium flow path 32. The inner seal member 46c may have a large R at the tip before lamination, and may have a small draft at the time of seal molding. The surface 14b is provided with an outer seal member 46d surrounding the oxidant gas inlet communication hole 22a, the oxidant gas outlet communication hole 22b, the fuel gas inlet communication hole 24a, and the fuel gas outlet communication hole 24b.

図４に示すように、外側シール部材４６ｂは、燃料ガス入口連通孔２４ａ、燃料ガス出口連通孔２４ｂ、冷却媒体入口連通孔２５ａ及び冷却媒体出口連通孔２５ｂ（以下、流体連通孔ともいう）を囲繞する。外側シール部材４６ｂは、酸化剤ガス入口連通孔２２ａ及び酸化剤ガス出口連通孔２２ｂ（以下、流体連通孔ともいう）と第１酸化剤ガス流路２６とを周回し、これらを互いに連通させる。 As shown in FIG. 4, the outer seal member 46b has a fuel gas inlet communication hole 24a, a fuel gas outlet communication hole 24b, a cooling medium inlet communication hole 25a, and a cooling medium outlet communication hole 25b (hereinafter also referred to as a fluid communication hole). Go. The outer seal member 46b circulates between the oxidant gas inlet communication hole 22a, the oxidant gas outlet communication hole 22b (hereinafter also referred to as a fluid communication hole) and the first oxidant gas flow path 26, and causes them to communicate with each other.

図１に示すように、外側シール部材４６ｄは、冷却面において、平面シール部４６ａから厚さ方向に一体に膨出形成され、流体連通孔、特に燃料ガス入口連通孔２４ａ及び燃料ガス出口連通孔２４ｂを囲繞する。外側シール部材４６ｄのシール幅ｈ１は、内側シール部材４６ｃのシール幅ｈ２よりも大きな寸法に設定される（ｈ１＞ｈ２）。なお、シール幅とは、平面部から立ち上がるＲ形状部を除いた位置で、両辺が互いに平行に延在する部分の幅寸法をいう。 As shown in FIG. 1, the outer seal member 46d is integrally bulged from the flat seal portion 46a in the thickness direction on the cooling surface, and is a fluid communication hole, particularly the fuel gas inlet communication hole 24a and the fuel gas outlet communication hole. 24b is surrounded. The seal width h1 of the outer seal member 46d is set to a dimension larger than the seal width h2 of the inner seal member 46c (h1> h2). The seal width means a width dimension of a portion where both sides extend in parallel with each other at a position excluding the R-shaped portion rising from the flat surface portion.

図２及び図３に示すように、第１金属セパレータ１４の面１４ａ側において、第１シール部材４６には、外側シール部材４６ｂの外方に位置して外周シール４６ｅが厚さ方向に一体成形される。 As shown in FIGS. 2 and 3, on the surface 14 a side of the first metal separator 14, an outer peripheral seal 46 e is integrally formed in the thickness direction on the first seal member 46 and located outside the outer seal member 46 b. Is done.

図１〜図３に示すように、第２シール部材４８は、均一の厚さを有して第２金属セパレータ１８の面１８ａ、１８ｂの面方向に沿って延在する平面シール部４８ａを有する。第２金属セパレータ１８の面１８ａにおいて、平面シール部４８ａからは、積層方向に沿って第１樹脂枠部材５８の外周縁部に重なり合う位置に、断面矩形状を有する内側シール部材４８ｂが厚さ方向に一体に膨出形成される。図３に示すように、内側シール部材４８ｂのシール幅ｈ３は、第１金属セパレータ１４の外周に設けられた外側シール部材４６ｂのシール幅ｈ４よりも小さな寸法に設定される（ｈ３＜ｈ４）。 As shown in FIGS. 1 to 3, the second seal member 48 has a flat seal portion 48 a having a uniform thickness and extending along the surface direction of the surfaces 18 a and 18 b of the second metal separator 18. . On the surface 18a of the second metal separator 18, the inner seal member 48b having a rectangular cross section is located in a thickness direction from the flat seal portion 48a at a position overlapping the outer peripheral edge portion of the first resin frame member 58 along the stacking direction. The bulge is formed integrally. As shown in FIG. 3, the seal width h3 of the inner seal member 48b is set to a size smaller than the seal width h4 of the outer seal member 46b provided on the outer periphery of the first metal separator 14 (h3 <h4).

第２金属セパレータ１８の面１８ｂには、第２樹脂枠部材６０の外方に且つ積層方向に沿って第３金属セパレータ２０に重なり合う位置に、断面矩形状の外側シール部材４８ｃが配置される。図５に示すように、外側シール部材４８ｃは、燃料ガス入口連通孔２４ａ、燃料ガス出口連通孔２４ｂ、冷却媒体入口連通孔２５ａ及び冷却媒体出口連通孔２５ｂを囲繞する。外側シール部材４８ｃは、酸化剤ガス入口連通孔２２ａ及び酸化剤ガス出口連通孔２２ｂと第２酸化剤ガス流路３８とを周回し、これらを互いに連通させる。 An outer seal member 48c having a rectangular cross section is disposed on the surface 18b of the second metal separator 18 at a position overlapping the third metal separator 20 outside the second resin frame member 60 and along the stacking direction. As shown in FIG. 5, the outer seal member 48c surrounds the fuel gas inlet communication hole 24a, the fuel gas outlet communication hole 24b, the cooling medium inlet communication hole 25a, and the cooling medium outlet communication hole 25b. The outer seal member 48 c circulates the oxidant gas inlet communication hole 22 a, the oxidant gas outlet communication hole 22 b, and the second oxidant gas flow path 38, and causes these to communicate with each other.

図２及び図３に示すように、第２金属セパレータ１８の面１８ａ側において、第２シール部材４８には、外側シール部材４８ｃの外方に位置して外周シール４８ｄが厚さ方向に一体成形される。第２金属セパレータ１８の面１８ｂ側において、第２シール部材４８には、外側シール部材４８ｃの外方に位置して外周シール４８ｅが厚さ方向に一体成形される。 As shown in FIGS. 2 and 3, on the surface 18a side of the second metal separator 18, an outer peripheral seal 48d is integrally formed in the thickness direction on the second seal member 48, located outside the outer seal member 48c. Is done. On the side of the surface 18b of the second metal separator 18, an outer peripheral seal 48e is integrally formed in the thickness direction on the second seal member 48, located outside the outer seal member 48c.

図１〜図３に示すように、第３シール部材５０は、均一の厚さを有して第３金属セパレータ２０の面２０ａ、２０ｂの面方向に沿って延在する平面シール部５０ａを有する。第３金属セパレータ２０の面２０ａにおいて、平面シール部５０ａからは、積層方向に沿って第２樹脂枠部材６０の外周縁部に重なり合う位置に、断面矩形状を有する内側シール部材５０ｂが厚さ方向に一体に膨出形成される。図３に示すように、内側シール部材５０ｂのシール幅ｈ５は、第２金属セパレータ１８の外周に設けられた外側シール部材４８ｃのシール幅ｈ６よりも小さな寸法に設定される（ｈ５＜ｈ６）。 As shown in FIGS. 1 to 3, the third seal member 50 has a flat seal portion 50 a having a uniform thickness and extending along the surface direction of the surfaces 20 a and 20 b of the third metal separator 20. . On the surface 20a of the third metal separator 20, the inner seal member 50b having a rectangular cross section is located in the thickness direction at a position overlapping the outer peripheral edge of the second resin frame member 60 along the stacking direction from the flat seal portion 50a. The bulge is formed integrally. As shown in FIG. 3, the seal width h5 of the inner seal member 50b is set to a size smaller than the seal width h6 of the outer seal member 48c provided on the outer periphery of the second metal separator 18 (h5 <h6).

第３金属セパレータ２０の面２０ｂには、第１樹脂枠部材５８及び第２樹脂枠部材６０の外方に且つ積層方向に沿って第１金属セパレータ１４に重なり合う位置に、断面矩形状の外側シール部材５０ｃが配置される。外側シール部材５０ｃは、酸化剤ガス入口連通孔２２ａ、酸化剤ガス出口連通孔２２ｂ、燃料ガス入口連通孔２４ａ及び燃料ガス出口連通孔２４ｂを囲繞する。外側シール部材５０ｃは、冷却媒体入口連通孔２５ａ及び冷却媒体出口連通孔２５ｂと冷却媒体流路３２とを周回し、これらを互いに連通させる。 An outer seal having a rectangular cross section is provided on the surface 20b of the third metal separator 20 at a position that overlaps the first metal separator 14 outside the first resin frame member 58 and the second resin frame member 60 and along the stacking direction. A member 50c is disposed. The outer seal member 50c surrounds the oxidant gas inlet communication hole 22a, the oxidant gas outlet communication hole 22b, the fuel gas inlet communication hole 24a, and the fuel gas outlet communication hole 24b. The outer seal member 50c circulates the cooling medium inlet communication hole 25a, the cooling medium outlet communication hole 25b, and the cooling medium flow path 32, and causes these to communicate with each other.

図２及び図３に示すように、第３金属セパレータ２０の面２０ａ側において、第３シール部材５０には、外側シール部材５０ｃの外方に位置して外周シール５０ｄが厚さ方向に一体成形される。第３金属セパレータ２０の面２０ｂ側において、第３シール部材５０には、外側シール部材５０ｃの外方に位置して外周シール５０ｅが厚さ方向に一体成形される。 As shown in FIGS. 2 and 3, on the surface 20a side of the third metal separator 20, the outer peripheral seal 50d is integrally formed in the thickness direction on the third seal member 50 and located outside the outer seal member 50c. Is done. On the surface 20b side of the third metal separator 20, an outer peripheral seal 50e is integrally formed on the third seal member 50 in the thickness direction so as to be located outside the outer seal member 50c.

第３シール部材５０の外周シール５０ｅは、隣接する第１金属セパレータ１４の第１シール部材４６に当接（密着）している。第１シール部材４６の外周シール（第２外周シール）４６ｅは、第２シール部材４８の外周シール（第１外周シール）４８ｄに当接（密着）している。第２シール部材４８の外周シール（第２外周シール）４８ｅは、第３シール部材５０の外周シール（第１外周シール）５０ｄに当接（密着）している。 The outer peripheral seal 50e of the third seal member 50 is in contact (contact) with the first seal member 46 of the adjacent first metal separator 14. The outer peripheral seal (second outer peripheral seal) 46e of the first seal member 46 is in contact (contact) with the outer peripheral seal (first outer peripheral seal) 48d of the second seal member 48. The outer peripheral seal (second outer peripheral seal) 48e of the second seal member 48 is in contact (contact) with the outer peripheral seal (first outer peripheral seal) 50d of the third seal member 50.

図１及び図２に示すように、第１樹脂枠付きＭＥＡ１６ａ及び第２樹脂枠付きＭＥＡ１６ｂは、それぞれ電解質膜・電極構造体５１を備える。電解質膜・電極構造体５１は、例えば、パーフルオロスルホン酸の薄膜に水が含浸された固体高分子電解質膜（陽イオン交換膜）５２と、前記固体高分子電解質膜５２を挟持するアノード電極５４及びカソード電極５６とを備える。 As shown in FIGS. 1 and 2, the MEA 16 a with the first resin frame and the MEA 16 b with the second resin frame each include an electrolyte membrane / electrode structure 51. The electrolyte membrane / electrode structure 51 includes, for example, a solid polymer electrolyte membrane (cation exchange membrane) 52 in which a perfluorosulfonic acid thin film is impregnated with water, and an anode electrode 54 sandwiching the solid polymer electrolyte membrane 52. And a cathode electrode 56.

固体高分子電解質膜５２は、フッ素系電解質の他、ＨＣ（炭化水素）系電解質を使用してもよい。カソード電極５６は、固体高分子電解質膜５２及びアノード電極５４よりも小さな平面寸法を有する段差ＭＥＡを構成する。 The solid polymer electrolyte membrane 52 may use an HC (hydrocarbon) electrolyte in addition to the fluorine electrolyte. The cathode electrode 56 constitutes a step MEA having a smaller planar dimension than the solid polymer electrolyte membrane 52 and the anode electrode 54.

なお、アノード電極５４、カソード電極５６及び固体高分子電解質膜５２は、同一の平面寸法に設定してもよい。また、アノード電極５４は、カソード電極５６及び固体高分子電解質膜５２の平面寸法よりも小さな平面寸法を有していてもよい。 The anode electrode 54, the cathode electrode 56, and the solid polymer electrolyte membrane 52 may be set to the same plane size. Further, the anode electrode 54 may have a plane size smaller than the plane size of the cathode electrode 56 and the solid polymer electrolyte membrane 52.

アノード電極５４及びカソード電極５６は、カーボンペーパ等からなるガス拡散層（図示せず）と、白金合金が表面に担持された多孔質カーボン粒子が前記ガス拡散層の表面に一様に塗布されて形成される電極触媒層（図示せず）とを有する。電極触媒層は、例えば、固体高分子電解質膜５２の両面に形成される。 The anode electrode 54 and the cathode electrode 56 are formed by uniformly applying a gas diffusion layer (not shown) made of carbon paper or the like and porous carbon particles carrying a platinum alloy on the surface thereof to the surface of the gas diffusion layer. And an electrode catalyst layer (not shown) to be formed. The electrode catalyst layer is formed on both surfaces of the solid polymer electrolyte membrane 52, for example.

第１樹脂枠付きＭＥＡ１６ａは、固体高分子電解質膜５２の外周を周回するとともに、アノード電極５４及びカソード電極５６に接合される第１樹脂枠部材５８を備える。第１樹脂枠部材５８は、例えば、ＰＰＳ（ポリフェニレンサルファイド）、ＰＰＡ（ポリフタルアミド）、ＰＥＮ（ポリエチレンナフタレート）、ＰＥＳ（ポリエーテルサルフォン）、ＬＣＰ（リキッドクリスタルポリマー）、ＰＶＤＦ（ポリフッ化ビニリデン）、シリコーンゴム、フッ素ゴム又はＥＰＤＭ（エチレンプロピレンゴム）等で構成される。 The MEA 16 a with the first resin frame includes a first resin frame member 58 that circulates around the outer periphery of the solid polymer electrolyte membrane 52 and is joined to the anode electrode 54 and the cathode electrode 56. The first resin frame member 58 includes, for example, PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyethersulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride). ), Silicone rubber, fluorine rubber or EPDM (ethylene propylene rubber).

第２樹脂枠付きＭＥＡ１６ｂは、固体高分子電解質膜５２の外周を周回するとともに、アノード電極５４及びカソード電極５６に接合される第２樹脂枠部材６０を備える。第２樹脂枠部材６０は、第１樹脂枠部材５８と同様に構成されており、その詳細な説明は省略する。 The MEA 16 b with the second resin frame includes a second resin frame member 60 that goes around the outer periphery of the solid polymer electrolyte membrane 52 and is joined to the anode electrode 54 and the cathode electrode 56. The second resin frame member 60 is configured in the same manner as the first resin frame member 58, and a detailed description thereof is omitted.

図１に示すように、第１樹脂枠部材５８のカソード電極５６側の面には、酸化剤ガス入口連通孔２２ａと第１酸化剤ガス流路２６の入口側との間に位置して入口バッファ部６２ａが設けられる。第１樹脂枠部材５８のカソード電極５６側の面には、酸化剤ガス出口連通孔２２ｂと第１酸化剤ガス流路２６の出口側との間に位置して、出口バッファ部６２ｂが設けられる。入口バッファ部６２ａ及び出口バッファ部６２ｂは、複数本のライン状凸部及びエンボス部を有するが、前記エンボス部のみを有してもよい。以下に説明するバッファ部は、同様に構成される。 As shown in FIG. 1, the inlet of the first resin frame member 58 on the cathode electrode 56 side is located between the oxidant gas inlet communication hole 22 a and the inlet side of the first oxidant gas flow path 26. A buffer unit 62a is provided. On the surface of the first resin frame member 58 on the cathode electrode 56 side, an outlet buffer portion 62b is provided between the oxidizing gas outlet communication hole 22b and the outlet side of the first oxidizing gas channel 26. . The inlet buffer 62a and the outlet buffer 62b have a plurality of line-shaped convex portions and embossed portions, but may have only the embossed portions. The buffer unit described below is configured similarly.

第１樹脂枠部材５８のアノード電極５４側の面には、燃料ガス入口連通孔２４ａと第１燃料ガス流路３４との間に位置して入口バッファ部６４ａが設けられる。第１樹脂枠部材５８のアノード電極５４側の面には、燃料ガス出口連通孔２４ｂと第１燃料ガス流路３４との間に位置して、出口バッファ部６４ｂが設けられる。 On the surface of the first resin frame member 58 on the anode electrode 54 side, an inlet buffer portion 64 a is provided between the fuel gas inlet communication hole 24 a and the first fuel gas flow path 34. On the surface of the first resin frame member 58 on the anode electrode 54 side, an outlet buffer portion 64 b is provided between the fuel gas outlet communication hole 24 b and the first fuel gas flow path 34.

第２樹脂枠付きＭＥＡ１６ｂに設けられる第２樹脂枠部材６０は、カソード電極５６側の面に、酸化剤ガス入口連通孔２２ａと第２酸化剤ガス流路３８との間に位置して入口バッファ部６６ａが設けられる。第２樹脂枠部材６０のカソード電極５６側の面には、酸化剤ガス出口連通孔２２ｂと第２酸化剤ガス流路３８との間に位置して、出口バッファ部６６ｂが形成される。 The second resin frame member 60 provided in the second resin frame-attached MEA 16b is located on the cathode electrode 56 side surface between the oxidant gas inlet communication hole 22a and the second oxidant gas flow path 38, and is an inlet buffer. A portion 66a is provided. On the surface of the second resin frame member 60 on the cathode electrode 56 side, an outlet buffer portion 66b is formed between the oxidant gas outlet communication hole 22b and the second oxidant gas flow path 38.

第２樹脂枠部材６０のアノード電極５４側の面には、燃料ガス入口連通孔２４ａと第２燃料ガス流路４２との間に位置して入口バッファ部６８ａが設けられる。第２樹脂枠部材６０のアノード電極５４側の面には、燃料ガス出口連通孔２４ｂと第２燃料ガス流路４２との間に位置して、出口バッファ部６８ｂが設けられる。 On the surface of the second resin frame member 60 on the anode electrode 54 side, an inlet buffer portion 68 a is provided between the fuel gas inlet communication hole 24 a and the second fuel gas flow path 42. On the surface of the second resin frame member 60 on the anode electrode 54 side, an outlet buffer portion 68 b is provided between the fuel gas outlet communication hole 24 b and the second fuel gas flow path 42.

発電ユニット１２同士が互いに積層されることにより、一方の発電ユニット１２を構成する第１金属セパレータ１４と、他方の発電ユニット１２を構成する第３金属セパレータ２０との間には、冷却媒体流路３２が形成される。 When the power generation units 12 are stacked on each other, a cooling medium flow path is provided between the first metal separator 14 constituting one power generation unit 12 and the third metal separator 20 constituting the other power generation unit 12. 32 is formed.

このように構成される燃料電池１０の動作について、以下に説明する。 The operation of the fuel cell 10 configured as described above will be described below.

先ず、図１に示すように、酸化剤ガス入口連通孔２２ａに酸素含有ガス等の酸化剤ガスが供給されるとともに、燃料ガス入口連通孔２４ａに水素含有ガス等の燃料ガスが供給される。さらに、一対の冷却媒体入口連通孔２５ａに純水やエチレングリコール、オイル等の冷却媒体が供給される。 First, as shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas inlet communication hole 22a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas inlet communication hole 24a. Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the pair of cooling medium inlet communication holes 25a.

このため、酸化剤ガスは、一部が酸化剤ガス入口連通孔２２ａから入口バッファ部６２ａを通って第１金属セパレータ１４の第１酸化剤ガス流路２６に供給される。酸化剤ガスは、他の一部が酸化剤ガス入口連通孔２２ａから入口バッファ部６６ａを通って第２金属セパレータ１８の第２酸化剤ガス流路３８に導入される。 Therefore, a part of the oxidant gas is supplied from the oxidant gas inlet communication hole 22a to the first oxidant gas flow path 26 of the first metal separator 14 through the inlet buffer 62a. Another part of the oxidant gas is introduced into the second oxidant gas flow path 38 of the second metal separator 18 from the oxidant gas inlet communication hole 22a through the inlet buffer portion 66a.

酸化剤ガスは、図１、図４及び図５に示すように、第１酸化剤ガス流路２６に沿って矢印Ｂ方向（水平方向）に移動し、第１樹脂枠付きＭＥＡ１６ａのカソード電極５６に供給される。また、酸化剤ガスは、第２酸化剤ガス流路３８に沿って矢印Ｂ方向に移動し、第２樹脂枠付きＭＥＡ１６ｂのカソード電極５６に供給される。 As shown in FIGS. 1, 4 and 5, the oxidant gas moves in the direction of arrow B (horizontal direction) along the first oxidant gas flow path 26, and the cathode electrode 56 of the first resin frame-equipped MEA 16a. To be supplied. The oxidant gas moves in the direction of arrow B along the second oxidant gas flow path 38, and is supplied to the cathode electrode 56 of the MEA 16b with the second resin frame.

一方、燃料ガスは、図１に示すように、燃料ガス入口連通孔２４ａから供給流路溝部３６ａ、４４ａに導入される。供給流路溝部３６ａでは、燃料ガスが、入口バッファ部６４ａを通って第２金属セパレータ１８の第１燃料ガス流路３４に供給される。供給流路溝部４４ａでは、燃料ガスが、入口バッファ部６８ａを通って第３金属セパレータ２０の第２燃料ガス流路４２に供給される。 On the other hand, as shown in FIG. 1, the fuel gas is introduced into the supply flow path grooves 36a and 44a from the fuel gas inlet communication hole 24a. In the supply flow path groove part 36a, the fuel gas is supplied to the first fuel gas flow path 34 of the second metal separator 18 through the inlet buffer part 64a. In the supply flow path groove 44a, the fuel gas is supplied to the second fuel gas flow path 42 of the third metal separator 20 through the inlet buffer portion 68a.

燃料ガスは、第１燃料ガス流路３４に沿って矢印Ｂ方向に移動し、第１樹脂枠付きＭＥＡ１６ａのアノード電極５４に供給される。また、燃料ガスは、第２燃料ガス流路４２に沿って矢印Ｂ方向に移動し、第２樹脂枠付きＭＥＡ１６ｂのアノード電極５４に供給される。 The fuel gas moves in the direction of arrow B along the first fuel gas flow path 34, and is supplied to the anode electrode 54 of the MEA 16a with the first resin frame. Further, the fuel gas moves in the direction of arrow B along the second fuel gas flow path 42 and is supplied to the anode electrode 54 of the MEA 16b with the second resin frame.

従って、第１樹脂枠付きＭＥＡ１６ａ及び第２樹脂枠付きＭＥＡ１６ｂでは、各カソード電極５６に供給される酸化剤ガスと、各アノード電極５４に供給される燃料ガスとが、電極触媒層内で電気化学反応により消費されて発電が行われる。 Therefore, in the MEA 16a with the first resin frame and the MEA 16b with the second resin frame, the oxidizing gas supplied to each cathode electrode 56 and the fuel gas supplied to each anode electrode 54 are electrochemically generated in the electrode catalyst layer. It is consumed by the reaction to generate electricity.

次いで、第１樹脂枠付きＭＥＡ１６ａ及び第２樹脂枠付きＭＥＡ１６ｂの各カソード電極５６に供給されて消費された酸化剤ガスは、出口バッファ部６２ｂ、６６ｂを通って酸化剤ガス出口連通孔２２ｂに排出される。第１樹脂枠付きＭＥＡ１６ａ及び第２樹脂枠付きＭＥＡ１６ｂのアノード電極５４に供給されて消費された燃料ガスは、出口バッファ部６４ｂ、６８ｂを通って燃料ガス出口連通孔２４ｂに排出される。 Next, the oxidant gas consumed by being supplied to the cathode electrodes 56 of the first resin frame-equipped MEA 16a and the second resin frame-equipped MEA 16b is discharged to the oxidant gas outlet communication hole 22b through the outlet buffer portions 62b and 66b. Is done. The fuel gas supplied to and consumed by the anode electrode 54 of the MEA 16a with the first resin frame and the MEA 16b with the second resin frame is discharged to the fuel gas outlet communication hole 24b through the outlet buffer portions 64b and 68b.

一方、左右一対の冷却媒体入口連通孔２５ａに供給された冷却媒体は冷却媒体流路３２に導入される。冷却媒体は、各冷却媒体入口連通孔２５ａから冷却媒体流路３２に供給され、一旦矢印Ｃ方向内方に沿って流動した後、矢印Ｂ方向に移動して第１樹脂枠付きＭＥＡ１６ａ及び第２樹脂枠付きＭＥＡ１６ｂを冷却する。この冷却媒体は、矢印Ｃ方向外方に移動した後、一対の冷却媒体出口連通孔２５ｂに排出される。 On the other hand, the cooling medium supplied to the pair of left and right cooling medium inlet communication holes 25 a is introduced into the cooling medium flow path 32. The cooling medium is supplied from each cooling medium inlet communication hole 25a to the cooling medium flow path 32 and once flows along the inner side in the direction of arrow C, then moves in the direction of arrow B to move the MEA 16a with the first resin frame and the second The MEA 16b with resin frame is cooled. This cooling medium moves outward in the direction of arrow C, and is then discharged into the pair of cooling medium outlet communication holes 25b.

この場合、本実施形態では、図２及び図３に示すように、第２金属セパレータ（第１のセパレータ）１８には、積層方向に沿って第１樹脂枠部材５８の外周縁部に重なり合う位置に、断面矩形状の内側シール部材４８ｂが配置されている。一方、第１金属セパレータ（第２のセパレータ）１４には、第１樹脂枠部材５８の外方に且つ積層方向に沿って第２金属セパレータ１８に重なり合う位置に、断面矩形状の外側シール部材４６ｂが配置されている。 In this case, in this embodiment, as shown in FIGS. 2 and 3, the second metal separator (first separator) 18 overlaps the outer peripheral edge of the first resin frame member 58 along the stacking direction. In addition, an inner seal member 48b having a rectangular cross section is disposed. On the other hand, the first metal separator (second separator) 14 has an outer seal member 46b having a rectangular cross section at a position overlapping the second metal separator 18 outside the first resin frame member 58 and along the stacking direction. Is arranged.

そして、外側シール部材４６ｂは、内側シール部材４８ｂの外周及び各流体連通孔を囲繞している。その際、外側シール部材４６ｂのシール幅ｈ４は、内側シール部材４８ｂのシール幅ｈ３よりも大きな寸法（ｈ３＜ｈ４）に設定されている（図３参照）。このため、簡単な構成で、反応ガス、特に燃料ガスが外部に透過することを可及的に抑制することが可能になるという効果が得られる。燃料ガスの透過とは、シール部材内部の透過と接触面からの透過とを含む。 The outer seal member 46b surrounds the outer periphery of the inner seal member 48b and each fluid communication hole. At that time, the seal width h4 of the outer seal member 46b is set to a dimension (h3 <h4) larger than the seal width h3 of the inner seal member 48b (see FIG. 3). For this reason, the effect that it becomes possible to suppress as much as possible that reaction gas, especially fuel gas permeate | transmits outside with a simple structure is acquired. The permeation of the fuel gas includes permeation inside the seal member and permeation from the contact surface.

また、第３金属セパレータ（第１のセパレータ）２０には、積層方向に沿って第２樹脂枠部材６０の外周縁部に重なり合う位置に、断面矩形状の内側シール部材５０ｂが配置されている。一方、第２金属セパレータ（第２のセパレータ）１８には、第２樹脂枠部材６０の外方に且つ積層方向に沿って第３金属セパレータ２０に重なり合う位置に、断面矩形状の外側シール部材４８ｃが配置されている。 The third metal separator (first separator) 20 is provided with an inner seal member 50b having a rectangular cross section at a position overlapping the outer peripheral edge of the second resin frame member 60 along the stacking direction. On the other hand, the second metal separator (second separator) 18 has an outer seal member 48c having a rectangular cross section at a position overlapping the third metal separator 20 outside the second resin frame member 60 and along the stacking direction. Is arranged.

そこで、外側シール部材４８ｃのシール幅ｈ６は、内側シール部材５０ｂのシール幅ｈ５よりも大きな寸法（ｈ５＜ｈ６）に設定されている（図３参照）。従って、簡単な構成で、反応ガス、特に燃料ガスが外部に透過することを可及的に抑制することが可能になるという効果が得られる。 Therefore, the seal width h6 of the outer seal member 48c is set to a dimension (h5 <h6) larger than the seal width h5 of the inner seal member 50b (see FIG. 3). Therefore, it is possible to obtain an effect that it is possible to suppress the permeation of the reaction gas, particularly the fuel gas, to the outside as much as possible with a simple configuration.

さらに、本実施形態では、図１に示すように、第１金属セパレータ１４の冷却面（面１４ｂ）において、内側シール部材４６ｃ、外側シール部材４６ｄが設けられている。そして、外側シール部材４６ｄのシール幅ｈ１は、内側シール部材４６ｃのシール幅ｈ２よりも大きな寸法（ｈ１＞ｈ２）に設定されている。これにより、簡単な構成で、反応ガス、特に燃料ガスが外部に透過することを可及的に抑制することが可能になるという効果が得られる。 Further, in the present embodiment, as shown in FIG. 1, an inner seal member 46 c and an outer seal member 46 d are provided on the cooling surface (surface 14 b) of the first metal separator 14. The seal width h1 of the outer seal member 46d is set to a dimension (h1> h2) larger than the seal width h2 of the inner seal member 46c. Thereby, it is possible to obtain the effect that it is possible to suppress the permeation of the reaction gas, particularly the fuel gas, to the outside as much as possible with a simple configuration.

なお、本実施形態では、発電ユニット１２は、３枚のセパレータと２枚の樹脂枠付きＭＥＡとを有し、各発電ユニット１２間に冷却媒体流路３２が形成されている（所謂、間引き冷却）。本発明は、これに限定されるものではなく、例えば、２枚のセパレータ間に１枚の樹脂枠付きＭＥＡが挟持される発電ユニット（所謂、各セル冷却）にも、適用することができる。 In the present embodiment, the power generation unit 12 has three separators and two MEAs with a resin frame, and a cooling medium flow path 32 is formed between the power generation units 12 (so-called thinning cooling). ). The present invention is not limited to this, and can also be applied to, for example, a power generation unit (so-called each cell cooling) in which one MEA with a resin frame is sandwiched between two separators.

また、本実施形態では、第１樹脂枠付きＭＥＡ１６ａ及び第２樹脂枠付きＭＥＡ１６ｂを用いているが、これに限定されるものではない。第１樹脂枠部材５８及び第２樹脂枠部材６０を不要にした電解質膜・電極構造体５１からなる、所謂、段差ＭＥＡを採用してもよい。 Moreover, in this embodiment, although MEA 16a with the 1st resin frame and MEA 16b with the 2nd resin frame are used, it is not limited to this. You may employ | adopt what is called level | step difference MEA which consists of the electrolyte membrane and electrode structure 51 which made the 1st resin frame member 58 and the 2nd resin frame member 60 unnecessary.

その際、第２金属セパレータ（第１のセパレータ）１８には、積層方向に沿って段差ＭＥＡの外周縁部に重なり合う位置に、断面矩形状の内側シール部材４８ｂが配置される。一方、第１金属セパレータ（第２のセパレータ）１４には、段差ＭＥＡの外方に且つ積層方向に沿って第２金属セパレータ１８に重なり合う位置に、断面矩形状の外側シール部材４６ｂが配置される。このため、上記の本願発明と同様の効果が得られる。 At that time, in the second metal separator (first separator) 18, an inner seal member 48b having a rectangular cross section is disposed at a position overlapping the outer peripheral edge of the step MEA along the stacking direction. On the other hand, in the first metal separator (second separator) 14, an outer seal member 46b having a rectangular cross section is disposed outside the step MEA and at a position overlapping the second metal separator 18 along the stacking direction. . For this reason, the same effect as the above-mentioned present invention can be obtained.

１０…燃料電池１２…発電ユニット
１４、１８、２０…金属セパレータ１６ａ、１６ｂ…樹脂枠付きＭＥＡ
２２ａ…酸化剤ガス入口連通孔２２ｂ…酸化剤ガス出口連通孔
２４ａ…燃料ガス入口連通孔２４ｂ…燃料ガス出口連通孔
２５ａ…冷却媒体入口連通孔２５ｂ…冷却媒体出口連通孔
２６、３８…酸化剤ガス流路３２…冷却媒体流路
３４、４２…燃料ガス流路４６、４８、５０…シール部材
４６ａ、４８ａ、５０ａ…平面シール部
４６ｂ、４６ｄ、４８ｃ、５０ｃ…外側シール部材
４６ｃ、４８ｂ、５０ｂ…内側シール部材
４６ｅ、４８ｄ、４８ｅ、５０ｄ、５０ｅ…外周シール
５１…電解質膜・電極構造体５２…固体高分子電解質膜
５４…アノード電極５６…カソード電極
５８、６０…樹脂枠部材 DESCRIPTION OF SYMBOLS 10 ... Fuel cell 12 ... Electric power generation unit 14, 18, 20 ... Metal separator 16a, 16b ... MEA with a resin frame
22a ... Oxidant gas inlet communication hole 22b ... Oxidant gas outlet communication hole 24a ... Fuel gas inlet communication hole 24b ... Fuel gas outlet communication hole 25a ... Cooling medium inlet communication hole 25b ... Cooling medium outlet communication hole 26, 38 ... Oxidant Gas passage 32 ... Cooling medium passage 34, 42 ... Fuel gas passage 46, 48, 50 ... Seal members 46a, 48a, 50a ... Planar seal portions 46b, 46d, 48c, 50c ... Outer seal members 46c, 48b, 50b ... inner seal members 46e, 48d, 48e, 50d, 50e ... outer peripheral seal 51 ... electrolyte membrane / electrode structure 52 ... solid polymer electrolyte membrane 54 ... anode electrode 56 ... cathode electrodes 58, 60 ... resin frame member

Claims

An MEA with a resin frame having an electrolyte membrane / electrode structure in which electrodes are arranged on both sides of the electrolyte membrane, a resin frame member provided around the outer periphery of the electrolyte membrane / electrode structure, and the MEA with the resin frame A first separator and a second separator that are stacked on both sides of the MEA with a resin frame.
The first separator and the second separator are fuel cells in which a plurality of fluid communication holes are formed to pass through the fuel gas, the oxidant gas, or the cooling medium, respectively, penetrating in the stacking direction.
In the first separator, an inner seal member having a rectangular cross section is disposed at a position overlapping the outer peripheral edge of the resin frame member along the stacking direction,
In the second separator, an outer seal member having a rectangular cross section is disposed outside the resin frame member and at a position overlapping the first separator along the stacking direction.
The outer seal member surrounds the outer periphery of the inner seal member and the fluid communication hole,
The fuel cell according to claim 1, wherein a seal width of the outer seal member is set to be larger than a seal width of the inner seal member.

2. The fuel cell according to claim 1, wherein a first outer peripheral seal is provided on an outer periphery of the first separator so as to be located outward of the outer seal member.
On the outer periphery of the second separator, a second outer peripheral seal is provided outside the outer seal member,
The fuel cell according to claim 1, wherein the first outer peripheral seal and the second outer peripheral seal overlap each other along the stacking direction.

An MEA with a resin frame having an electrolyte membrane / electrode structure in which electrodes are arranged on both sides of the electrolyte membrane, a resin frame member provided around the outer periphery of the electrolyte membrane / electrode structure, and the MEA with the resin frame A first separator and a second separator that are stacked on both sides of the MEA with a resin frame.
The first separator and the second separator are fuel cells in which a plurality of fluid communication holes are formed to pass through the fuel gas, the oxidant gas, or the cooling medium, respectively, penetrating in the stacking direction.
Either one of the first separator and the second separator is provided with an inner seal member having a rectangular cross section disposed at a position overlapping the outer peripheral edge of the resin frame member along the stacking direction,
On the other side, an outer seal member having a rectangular cross section disposed to surround the fluid communication hole is provided,
The fuel cell according to claim 1, wherein a seal width of the outer seal member is set to be larger than a seal width of the inner seal member.

An electrolyte membrane / electrode structure having electrodes disposed on both sides of the electrolyte membrane, and has an outer dimension larger than the outer dimension of the electrolyte membrane / electrode structure, and is laminated on both sides of the electrolyte membrane / electrode structure. A first separator and a second separator,
The first separator and the second separator are fuel cells in which a plurality of fluid communication holes are formed to pass through the fuel gas, the oxidant gas, or the cooling medium, respectively, penetrating in the stacking direction.
In the first separator, an inner seal member having a rectangular cross section is disposed at a position overlapping the outer peripheral edge of the electrolyte membrane / electrode structure along the stacking direction,
The second separator is located outside the electrolyte membrane / electrode structure and at a position that overlaps the first separator along the stacking direction and does not overlap the electrolyte membrane / electrode structure. An outer seal member having a rectangular cross section is disposed,
The outer seal member surrounds the outer periphery of the inner seal member and the fluid communication hole,
The fuel cell according to claim 1, wherein a seal width of the outer seal member is set to be larger than a seal width of the inner seal member.