JP2011018605A - Fuel cell - Google Patents

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JP2011018605A
JP2011018605A JP2009163568A JP2009163568A JP2011018605A JP 2011018605 A JP2011018605 A JP 2011018605A JP 2009163568 A JP2009163568 A JP 2009163568A JP 2009163568 A JP2009163568 A JP 2009163568A JP 2011018605 A JP2011018605 A JP 2011018605A
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cathode
fuel cell
electrode
gas
catalyst
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Masahiro Shiozawa
方浩 塩澤
Kazuya Yamashita
和也 山下
Toshiya Habu
敏也 土生
Yuki Ishigaki
有基 石垣
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Toyota Motor Corp
Soken Inc
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Nippon Soken Inc
Toyota Motor Corp
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

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Abstract

PROBLEM TO BE SOLVED: To provide a technology to suppress the deterioration of the power generation performance of a fuel cell.SOLUTION: The fuel cell 100 includes a membrane electrode conjugate 10 in which an electrolyte film 1 is held between an anode electrode 2 and a cathode electrode 3, and a gas flow passage for an oxidizing agent gas provided along an electrode surface of the cathode electrode 3. The cathode electrode 3 includes a catalyst-carrying carbon carrying catalyst to promote a power generation reaction, and a polymer electrolyte. Furthermore, the cathode electrode 3 is equipped with a first cathode region 3a provided at an upstream side of the gas flow passage, and a second cathode region 3b provided at a downstream side of the gas flow passage. A quantity of the polymer electrolyte with respect to the quantity of the catalyst-carrying carbon in the first cathode region 3a is smaller than that in the second cathode region.

Description

この発明は、燃料電池に関する。   The present invention relates to a fuel cell.

燃料電池は、通常、電解質膜の両面に電極が配置された発電体である膜電極接合体を備えている（下記特許文献１等）。電解質膜としては湿潤状態で良好なイオン伝導性を示す膜が用いられる。そのため、燃料電池の運転の際には、燃料電池内部は適度な湿潤状態に保たれることが好ましい。   A fuel cell normally includes a membrane electrode assembly which is a power generator in which electrodes are arranged on both surfaces of an electrolyte membrane (Patent Document 1 below). As the electrolyte membrane, a membrane showing good ion conductivity in a wet state is used. For this reason, it is preferable that the inside of the fuel cell be kept in a moderately wet state during operation of the fuel cell.

しかし、膜電極接合体では、反応ガス（燃料ガスおよび酸化剤ガス）の流れに従って水分が移動するため、反応ガスの上流側ほど電解質膜が乾燥しやすい傾向にある。燃料電池に供給される反応ガスの加湿量が低いほど、水分の蒸発が促進されるため、その傾向が特に強くなる。電解質膜の乾燥が著しい場合には、イオン伝導性の低下により発電不能に陥る、いわゆるドライアップが発生し、燃料電池の発電性能の低下が引き起こされる可能性がある。   However, in the membrane electrode assembly, the moisture moves according to the flow of the reaction gas (fuel gas and oxidant gas), and therefore the electrolyte membrane tends to dry more toward the upstream side of the reaction gas. This tendency is particularly strong as the moisture content of the reaction gas supplied to the fuel cell is lower, since moisture evaporation is promoted. When the electrolyte membrane is extremely dried, so-called dry-up occurs, in which power generation becomes impossible due to a decrease in ion conductivity, which may cause a decrease in power generation performance of the fuel cell.

特開２００６−０１２４７６号公報JP 2006-012476 A 特開２００８−１７６９９０号公報JP 2008-176990 A 特開２００７−０８０６９４号公報JP 2007-080694 A

本発明は、燃料電池の発電性能の低下を抑制する技術を提供することを目的とする。   An object of this invention is to provide the technique which suppresses the fall of the electric power generation performance of a fuel cell.

本発明は、上述の課題の少なくとも一部を解決するためになされたものであり、以下の形態又は適用例として実現することが可能である。   SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

［適用例１］
燃料ガスおよび酸化剤ガスの供給を受けて発電する燃料電池であって、電解質膜がアノード電極およびカソード電極によって狭持された膜電極接合体と、前記カソード電極の電極面に沿って設けられた酸化剤ガスのためのガス流路とを備え、前記カソード電極は、発電反応を促進するための触媒が担持された触媒担持カーボンと、高分子電解質とを含むとともに、前記ガス流路の上流側に設けられた第１のカソード領域と、前記ガス流路の下流側に設けられた第２のカソード領域とを有し、前記第１のカソード領域は前記触媒担持カーボンに対する前記高分子電解質の量が前記第２のカソード領域より少ない、燃料電池。
この燃料電池によれば、高分子電解質の含有量が少なく、排水性が比較的低い第１のカソード領域がガス流路の上流側に設けられているため、カソード電極の上流側における保水性が向上する。従って、カソード電極の上流側が乾燥することによる燃料電池の発電性能の低下を抑制できる。 [Application Example 1]
A fuel cell that generates electric power by being supplied with a fuel gas and an oxidant gas, wherein an electrolyte membrane is provided between an anode electrode and a cathode electrode, and a membrane electrode assembly is provided along the electrode surface of the cathode electrode A gas flow path for an oxidant gas, wherein the cathode electrode includes a catalyst-carrying carbon on which a catalyst for promoting a power generation reaction is supported, a polymer electrolyte, and an upstream side of the gas flow path A first cathode region provided on the downstream side of the gas flow path and a second cathode region provided downstream of the gas flow path, wherein the first cathode region is an amount of the polymer electrolyte relative to the catalyst-supporting carbon. A fuel cell having less than said second cathode region.
According to this fuel cell, since the first cathode region having a low content of polymer electrolyte and relatively low drainage is provided on the upstream side of the gas flow path, the water retention on the upstream side of the cathode electrode is ensured. improves. Therefore, it is possible to suppress a decrease in power generation performance of the fuel cell due to drying of the upstream side of the cathode electrode.

なお、本発明は、種々の形態で実現することが可能であり、例えば、燃料電池、その燃料電池を備えた燃料電池システム、その燃料電池システムを搭載した車両等の形態で実現することができる。   The present invention can be realized in various forms, for example, in the form of a fuel cell, a fuel cell system including the fuel cell, a vehicle equipped with the fuel cell system, and the like. .

燃料電池の構成を示す概略図。Schematic which shows the structure of a fuel cell. カソード電極におけるアイオノマー比と排水量との関係を示す説明図。Explanatory drawing which shows the relationship between the ionomer ratio in a cathode electrode, and the amount of drainage.

A．実施例：
図１は本発明の一実施例としての燃料電池の構成を示す概略図である。この燃料電池１００は、反応ガスとして水素と空気の供給を受けて発電する固体高分子型燃料電池である。燃料電池１００は、膜電極接合体１０と、２つのガス拡散部材４１，４２と、アノードセパレータ５０と、カソードセパレータ６０とを備える。なお、燃料電池１００は、複数の膜電極接合体１０がセパレータを介して積層される燃料電池スタックとして構成されるものとしても良い。 A. Example:
FIG. 1 is a schematic diagram showing the configuration of a fuel cell as an embodiment of the present invention. The fuel cell 100 is a polymer electrolyte fuel cell that generates power by receiving supply of hydrogen and air as reaction gases. The fuel cell 100 includes a membrane electrode assembly 10, two gas diffusion members 41 and 42, an anode separator 50, and a cathode separator 60. The fuel cell 100 may be configured as a fuel cell stack in which a plurality of membrane electrode assemblies 10 are stacked via separators.

膜電極接合体１０は、電解質膜１がアノード電極２およびカソード電極３によって狭持された発電体である。電解質膜１は、湿潤状態で良好なプロトン伝導性を示す固体高分子薄膜である。アノード電極２およびカソード電極３は、触媒インクを電解質膜１の外表面に塗布・乾燥させることによって形成されたガス透過性を有する電極である。ここで、「触媒インク」とは、発電反応を促進するための触媒（例えば白金（Ｐｔ）など）が担持された触媒担持カーボンと高分子電解質溶液とを混合した混合溶液を意味する。なお、本実施例の燃料電池１００では、カソード電極３に第１と第２のカソード領域３ａ，３ｂが設けられているが、詳細は後述する。   The membrane electrode assembly 10 is a power generator in which the electrolyte membrane 1 is held between the anode electrode 2 and the cathode electrode 3. The electrolyte membrane 1 is a solid polymer thin film that exhibits good proton conductivity in a wet state. The anode electrode 2 and the cathode electrode 3 are electrodes having gas permeability formed by applying and drying catalyst ink on the outer surface of the electrolyte membrane 1. Here, the “catalyst ink” means a mixed solution in which a catalyst-carrying carbon carrying a catalyst (for example, platinum (Pt)) for promoting a power generation reaction is mixed with a polymer electrolyte solution. In the fuel cell 100 of the present embodiment, the cathode electrode 3 is provided with first and second cathode regions 3a and 3b, which will be described in detail later.

２つのガス拡散部材４１，４２はそれぞれ、ガス透過性および導電性を有する多孔質部材であり、アノード電極２またはカソード電極３の全体に反応ガスを行き渡らせるためのガス流路として機能する。第１のガス拡散部材４１はアノード電極２の外側に配置され、第２のガス拡散部材４２はカソード電極３の外側に配置される。２つのガス拡散部材４１，４２は、カーボンペーパーや、カーボンクロス、いわゆるエキスパンドメタル、パンチングメタルなどによって構成することができる。   Each of the two gas diffusion members 41 and 42 is a porous member having gas permeability and conductivity, and functions as a gas flow path for spreading the reaction gas over the entire anode electrode 2 or cathode electrode 3. The first gas diffusion member 41 is disposed outside the anode electrode 2, and the second gas diffusion member 42 is disposed outside the cathode electrode 3. The two gas diffusion members 41 and 42 can be made of carbon paper, carbon cloth, so-called expanded metal, punching metal, or the like.

アノードセパレータ５０およびカソードセパレータ６０は、導電性を有するガス不透過の板状部材である。アノードセパレータ５０およびカソードセパレータ６０はそれぞれ、第１と第２のガス拡散部材４１，４２の外側から膜電極接合体１０を狭持する。アノードセパレータ５０およびカソードセパレータ６０の内側（膜電極接合体１０の側）の面にはそれぞれ、反応ガスのための流路溝５１，６１が設けられている。   The anode separator 50 and the cathode separator 60 are gas-impermeable plate-like members having conductivity. The anode separator 50 and the cathode separator 60 sandwich the membrane electrode assembly 10 from the outside of the first and second gas diffusion members 41 and 42, respectively. Flow channel grooves 51 and 61 for the reaction gas are provided on the surfaces of the anode separator 50 and the cathode separator 60 (on the side of the membrane electrode assembly 10), respectively.

アノードセパレータ５０の流路溝５１は、図１の紙面垂直方向に沿って交互にジグザグに折り返す、いわゆるサーペンタイン形状の流路溝であり、発電領域の全体に渡って形成されている。反応ガスである水素は、流路溝５１の端部５２（図１の紙面上側）から供給され、流路溝５１に沿って図１の紙面下側へと流れつつ、ガス拡散部材４１を介してアノード電極２に至り、発電反応に供される。反応に供されることのなかった水素を含むアノード排ガスは、ガス拡散部材４１を介して流路溝５１へと流れ、流路溝５１の端部５３（図１の紙面下側）から燃料電池１００の外部へと排出される。   The channel groove 51 of the anode separator 50 is a so-called serpentine-shaped channel groove that is alternately folded in a zigzag manner along the direction perpendicular to the plane of FIG. 1 and is formed over the entire power generation region. Hydrogen, which is a reactive gas, is supplied from the end 52 (upper side of the drawing in FIG. 1) of the flow channel 51 and flows along the flow channel 51 to the lower side of the drawing in FIG. As a result, it reaches the anode electrode 2 and is subjected to a power generation reaction. The anode exhaust gas containing hydrogen that has not been subjected to the reaction flows to the flow channel 51 through the gas diffusion member 41, and the fuel cell from the end 53 of the flow channel 51 (lower side in FIG. 1). 100 is discharged to the outside.

カソードセパレータ６０の流路溝６１は、アノードセパレータ５０の流路溝５１と、膜電極接合体１０を挟んで対称に形成されたサーペンタイン形状の流路溝である。反応ガスである空気は、流路溝６１の端部６２（図１紙面下側）から供給され、流路溝６１に沿って図１の紙面上側へと流れつつ、ガス拡散部材４１を介してカソード電極３に至り、発電反応に供される。反応に供されることのなかった酸素および発電反応によって生成された水分を含むカソード排ガスは、ガス拡散部材４１を介して流路溝６１へと流れ、流路溝６１の端部６３（図１の紙面上側）から燃料電池１００の外部へと排出される。   The channel groove 61 of the cathode separator 60 is a serpentine-shaped channel groove formed symmetrically with the channel groove 51 of the anode separator 50 and the membrane electrode assembly 10 interposed therebetween. Air, which is a reaction gas, is supplied from the end 62 (lower side of the drawing in FIG. 1) of the flow channel 61 and flows along the flow channel 61 to the upper side of the drawing in FIG. It reaches the cathode electrode 3 and is subjected to a power generation reaction. The cathode exhaust gas containing oxygen that has not been subjected to the reaction and moisture generated by the power generation reaction flows to the flow channel 61 through the gas diffusion member 41, and ends 63 (FIG. 1) of the flow channel 61 From the upper side of the paper) to the outside of the fuel cell 100.

即ち、この燃料電池１００では、２つの電極２，３と、ガス拡散部材４１，４２と、各セパレータ４０，６０の流路溝５１，５２とによって、電極面に沿った反応ガスのための流路が形成されており、水素の流れ方向と酸素の流れ方向とが互いに対向し合っている。なお、各セパレータの流路溝５１，５２の形状はサーペンタイン形状でなくとも良く、例えば、図１の紙面上下方向に複数の流路溝が併走する直線形状の流路溝であっても良い。また、各セパレータの流路溝５１，５２とガス拡散部材４１，４２とのうち、いずれか一方が省略されるものとしても良い。   That is, in this fuel cell 100, the flow for the reaction gas along the electrode surface is achieved by the two electrodes 2 and 3, the gas diffusion members 41 and 42, and the flow channel grooves 51 and 52 of the separators 40 and 60. A passage is formed, and the flow direction of hydrogen and the flow direction of oxygen are opposed to each other. In addition, the shape of the flow channel grooves 51 and 52 of each separator may not be a serpentine shape, and may be, for example, a linear flow channel groove in which a plurality of flow channel grooves run in the vertical direction in FIG. Further, either one of the flow path grooves 51 and 52 and the gas diffusion members 41 and 42 of each separator may be omitted.

ところで、一般に、燃料電池では、カソード電極面における反応ガスの上流側ほど電解質膜が乾燥しやすい傾向にある。特に、燃料電池に無加湿の反応ガスが供給される場合など、供給される反応ガスの湿潤度が低いほど、上流側における水分の蒸発が促進されるため、この傾向が強くなる。電解質膜の乾燥が著しい場合には、プロトン伝導性の低下により、燃料電池が発電停止に陥ってしまう場合がある。従って、カソード電極面における反応ガスの上流側においては、水分の蒸発を抑制し、排水性が低下されていることが好ましい。   By the way, in general, in the fuel cell, the electrolyte membrane tends to be dried more toward the upstream side of the reaction gas on the cathode electrode surface. In particular, when the non-humidified reaction gas is supplied to the fuel cell, the lower the wetness of the supplied reaction gas is, the more moisture is promoted on the upstream side, and this tendency becomes stronger. When the electrolyte membrane is significantly dried, the fuel cell may stop generating power due to a decrease in proton conductivity. Therefore, on the upstream side of the reaction gas on the cathode electrode surface, it is preferable that the evaporation of moisture is suppressed and the drainage is reduced.

前述したように、カソード電極３は、触媒担持カーボンと、高分子電解質とを含む。ここで、本明細書では、触媒担持カーボンの質量に対する高分子電解質の質量の比を「アイオノマー比」と呼ぶ。本発明の発明者は、このアイオノマー比とカソード電極の排水性との間には、次のような関係があることを見出した。   As described above, the cathode electrode 3 includes catalyst-supporting carbon and a polymer electrolyte. Here, in this specification, the ratio of the mass of the polymer electrolyte to the mass of the catalyst-supporting carbon is referred to as “ionomer ratio”. The inventor of the present invention has found that the following relationship exists between the ionomer ratio and the drainage of the cathode electrode.

図２は、カソード電極における排水量とカソード電極のアイオノマー比との関係を示すグラフである。本発明の発明者は、アイオノマー比がそれぞれＫ1，Ｋ2，Ｋ3である触媒インクを用いて、アイオノマー比が異なるカソード電極を有する３種類の燃料電池を構成し、各燃料電池において同条件での発電を行い、カソード排ガスに含まれる水分量（排水量）を測定した。なお、この測定に用いられた各燃料電池は、カソード電極以外の構成が、本実施例の燃料電池１００とほぼ同じである。 FIG. 2 is a graph showing the relationship between the amount of drainage at the cathode electrode and the ionomer ratio of the cathode electrode. The inventor of the present invention constructed three types of fuel cells having cathode electrodes with different ionomer ratios using catalyst inks having ionomer ratios of K 1 , K 2 , and K 3 , respectively. The amount of water contained in the cathode exhaust gas (drainage amount) was measured. In addition, each fuel cell used for this measurement has substantially the same configuration as the fuel cell 100 of the present embodiment except for the cathode electrode.

測定にあたり、各燃料電池には、カソード側にストイキ比４．５の量の室温の空気を背圧１００ｋＰａＧで供給し、アノード側にストイキ比３．５の量の室温の水素を背圧１００ｋＰａＧで供給した。また、各燃料電池には、０．１Ａの一定電流で発電させた。このグラフＧから、カソード電極のアイオノマー比が小さい燃料電池ほど排水量が少なく、発電によって生成された水分が燃料電池内に保持されていることがわかる。即ち、アイオノマー比が小さいカソード電極ほど、生成水分の蒸発が抑制され、その排水性が低下している。   In measurement, each fuel cell is supplied with room-temperature air having a stoichiometric ratio of 4.5 to the cathode side at a back pressure of 100 kPaG, and room temperature hydrogen having a stoichiometric ratio of 3.5 to the anode side at a back pressure of 100 kPaG. Supplied. Each fuel cell was generated at a constant current of 0.1A. From this graph G, it can be seen that a fuel cell with a smaller ionomer ratio of the cathode electrode has a smaller amount of drainage, and water generated by power generation is retained in the fuel cell. That is, the smaller the ionomer ratio, the more the generated water is prevented from evaporating and the drainage is reduced.

ここで、本実施例の燃料電池１００（図１）では、カソード電極３に第１と第２のカソード領域３ａ，３ｂが設けられている。第１のカソード領域３ａは、カソード電極３の上流側（図１の紙面下側）に設けられた領域であり、第２のカソード領域３ｂは、カソード電極３の下流側（図１の紙面上側）に設けられた領域である。第１と第２のカソード領域３ａ，３ｂはそれぞれ、アイオノマー比の異なる触媒インクを用いることにより形成されており、第１のカソード領域３ａは、第２のカソード領域３ｂよりアイオノマー比の小さい領域として形成されている。即ち、この燃料電池１００では、カソード電極３の上流側に、高分子電解質の含有量が比較的少なく、排水性が比較的低い第１のカソード領域３ａが形成されている。この第１のカソード領域３ａによって、カソード電極３の上流側における保水性が向上し、電解質膜１の乾燥が抑制され、運転中の燃料電池１００における発電性能の低下が抑制される。   Here, in the fuel cell 100 (FIG. 1) of the present embodiment, the cathode electrode 3 is provided with first and second cathode regions 3a and 3b. The first cathode region 3a is a region provided on the upstream side of the cathode electrode 3 (the lower side of the drawing in FIG. 1), and the second cathode region 3b is the downstream side of the cathode electrode 3 (the upper side of the drawing in FIG. 1). ). The first and second cathode regions 3a and 3b are formed by using catalyst inks having different ionomer ratios, and the first cathode region 3a is a region having an ionomer ratio smaller than that of the second cathode region 3b. Is formed. That is, in the fuel cell 100, the first cathode region 3a having a relatively low content of the polymer electrolyte and a relatively low drainage property is formed on the upstream side of the cathode electrode 3. The first cathode region 3a improves water retention on the upstream side of the cathode electrode 3, suppresses drying of the electrolyte membrane 1, and suppresses a decrease in power generation performance in the operating fuel cell 100.

ところで、一般に、燃料電池では、各電極に含まれる触媒量を低減すると、触媒あたりの発電反応による発熱量が増大するため、カソード電極がより乾燥しやすくなることが知られている。カソード電極が乾燥すると、カソード電極に含まれる高分子電解質のガス透過性が低下し、反応ガスの配流性が低下するため、燃料電池の発電性能が低下してしまう。しかし、本実施例の燃料電池１００によれば、第１のカソード領域３ａによって、カソード電極３の保水性が向上しているため、カソード電極３に含まれる触媒量を低減した場合であっても、カソード電極３の上流側における乾燥を抑制することができる。従って、燃料電池１００の発電性能の低下を抑制しつつ、触媒使用量の削減による製造コストの低減が可能である。   By the way, in general, in a fuel cell, it is known that when the amount of catalyst contained in each electrode is reduced, the amount of heat generated by the power generation reaction per catalyst increases, so that the cathode electrode becomes easier to dry. When the cathode electrode is dried, the gas permeability of the polymer electrolyte contained in the cathode electrode is lowered and the flowability of the reaction gas is lowered, so that the power generation performance of the fuel cell is lowered. However, according to the fuel cell 100 of the present embodiment, the water retention of the cathode electrode 3 is improved by the first cathode region 3a, so even if the amount of catalyst contained in the cathode electrode 3 is reduced. Further, drying on the upstream side of the cathode electrode 3 can be suppressed. Therefore, it is possible to reduce the manufacturing cost by reducing the amount of catalyst used while suppressing a decrease in the power generation performance of the fuel cell 100.

ここで、第１と第２のカソード領域３ａ，３ｂのそれぞれのアイオノマー比は、以下に説明する方法により設定することが好ましい。アイオノマー比が発電領域に渡って均一となるようにカソード電極を構成した場合に、燃料電池の発電性能が最も向上する好適なアイオノマー比Ｋstdを実験により求める。そして、第１のカソード領域３ａのアイオノマー比Ｋaをアイオノマー比Ｋstdより小さく設定し、第２のカソード領域３ｂのアイオノマー比Ｋbを アイオノマー比Ｋstdより大きく設定する（Ｋa＜Ｋstd＜Ｋb）。これによって、燃料電池１００の発電性能を、より向上させることができる。 Here, the ionomer ratio of each of the first and second cathode regions 3a and 3b is preferably set by the method described below. When the cathode electrode is configured so that the ionomer ratio is uniform over the power generation region, a suitable ionomer ratio K std that provides the most improved power generation performance of the fuel cell is obtained by experiments. Then, the ionomer ratio K a of the first cathode region 3a is set smaller than the ionomer ratio K std, the ionomer ratio K b of the second cathode region 3b is set greater than the ionomer ratio K std (K a <K std < K b ). Thereby, the power generation performance of the fuel cell 100 can be further improved.

なお、カソード電極３は、第１と第２のカソード領域３ａ，３ｂ以外に、アイオノマー比の異なる複数の領域をさらに有しているものとしても良い。また、第１と第２のカソード領域３ａ，３ｂのように、アイオノマー比の異なる領域が明確に区分けされていなくとも良い。例えば、カソード電極３は、反応ガスの上流側ほどアイオノマー比が小さくなるように構成されているものとしても良い。   The cathode electrode 3 may further include a plurality of regions having different ionomer ratios in addition to the first and second cathode regions 3a and 3b. In addition, regions having different ionomer ratios such as the first and second cathode regions 3a and 3b may not be clearly divided. For example, the cathode electrode 3 may be configured such that the ionomer ratio becomes smaller toward the upstream side of the reaction gas.

このように、本実施例の燃料電池１００によれば、アイオノマー比が比較的小さい第１のカソード領域３ａによってカソード電極３の上流側の排水性を低下させることにより、燃料電池１００の発電性能の低下を抑制できる。なお、本実施例の燃料電池１００は、反応ガスを無加湿で供給する燃料電池システムに用いた場合に、特に、その発電性能の低下が抑制される。   As described above, according to the fuel cell 100 of the present embodiment, the first cathode region 3a having a relatively small ionomer ratio reduces the drainage performance on the upstream side of the cathode electrode 3, thereby improving the power generation performance of the fuel cell 100. Reduction can be suppressed. In addition, when the fuel cell 100 of the present embodiment is used in a fuel cell system that supplies the reaction gas without humidification, a decrease in the power generation performance is suppressed.

１…電解質膜
２…アノード電極
３…カソード電極
３ａ…第１のカソード領域
３ｂ…第２のカソード領域
１０…膜電極接合体
４１…第１のガス拡散部材
４２…第２のガス拡散部材
５０…アノードセパレータ
５１…流路溝
５２…端部
５３…端部
６０…カソードセパレータ
６１…流路溝
６２…端部
６３…端部
１００…燃料電池 DESCRIPTION OF SYMBOLS 1 ... Electrolyte membrane 2 ... Anode electrode 3 ... Cathode electrode 3a ... 1st cathode area | region 3b ... 2nd cathode area | region 10 ... Membrane electrode assembly 41 ... 1st gas diffusion member 42 ... 2nd gas diffusion member 50 ... Anode separator 51 ... channel groove 52 ... end 53 ... end 60 ... cathode separator 61 ... channel groove 62 ... end 63 ... end 100 ... fuel cell

Claims (1)

燃料ガスおよび酸化剤ガスの供給を受けて発電する燃料電池であって、
電解質膜がアノード電極およびカソード電極によって狭持された膜電極接合体と、
前記カソード電極の電極面に沿って設けられた酸化剤ガスのためのガス流路と、
を備え、
前記カソード電極は、発電反応を促進するための触媒が担持された触媒担持カーボンと、高分子電解質とを含むとともに、前記ガス流路の上流側に設けられた第１のカソード領域と、前記ガス流路の下流側に設けられた第２のカソード領域とを有し、
前記第１のカソード領域は前記触媒担持カーボンに対する前記高分子電解質の量が前記第２のカソード領域より少ない、燃料電池。 A fuel cell that generates power by receiving supply of fuel gas and oxidant gas,
A membrane electrode assembly in which an electrolyte membrane is sandwiched between an anode electrode and a cathode electrode;
A gas flow path for an oxidant gas provided along the electrode surface of the cathode electrode;
With
The cathode electrode includes a catalyst-supporting carbon on which a catalyst for promoting a power generation reaction is supported, a polymer electrolyte, a first cathode region provided on the upstream side of the gas flow path, and the gas A second cathode region provided on the downstream side of the flow path,
The first cathode region is a fuel cell, wherein the amount of the polymer electrolyte with respect to the catalyst-supporting carbon is less than that of the second cathode region.
JP2009163568A 2009-07-10 2009-07-10 Fuel cell Withdrawn JP2011018605A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012186105A (en) * 2011-03-08 2012-09-27 Nippon Soken Inc Fuel cell
JP2017041403A (en) * 2015-08-21 2017-02-23 トヨタ車体株式会社 Gas passage formation plate for fuel battery and fuel battery stack

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012186105A (en) * 2011-03-08 2012-09-27 Nippon Soken Inc Fuel cell
JP2017041403A (en) * 2015-08-21 2017-02-23 トヨタ車体株式会社 Gas passage formation plate for fuel battery and fuel battery stack
US10109868B2 (en) 2015-08-21 2018-10-23 Toyota Shatai Kabushiki Kaisha Gas channel forming plate for fuel cell and fuel cell stack

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