JP2006004702A - Separator for solid polymer fuel cell - Google Patents

Separator for solid polymer fuel cell Download PDF

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JP2006004702A
JP2006004702A JP2004178282A JP2004178282A JP2006004702A JP 2006004702 A JP2006004702 A JP 2006004702A JP 2004178282 A JP2004178282 A JP 2004178282A JP 2004178282 A JP2004178282 A JP 2004178282A JP 2006004702 A JP2006004702 A JP 2006004702A
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separator
gas
fuel cell
inlet
outlet
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Shinichi Kamoshita
真一 鴨志田
Yoshikazu Morita
芳和 守田
Keiji Izumi
圭二 和泉
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Nippon Steel Nisshin Co Ltd
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Nisshin Steel Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
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    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

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Abstract

<P>PROBLEM TO BE SOLVED: To provide a separator for a solid polymer fuel cell having a gas passageway which efficiently discharge condensation liquid water from the interior of a battery out of a system while raising the proportion of fuel gas consumed by a cell reaction and an oxidizing agent. <P>SOLUTION: The separator has an input side passage 20 and an output side passage 30 which are separated from one another. The branch way 23 of the input side passage 20 communicates with the assembled part 32 of the output side passage 30 through a drain gutter 24 formed at a tip. The cross sectional area of the drain gutter 24 is reduced smaller than the branch way 23 so that the flowing velocity of a gas stream which flows the drain gutter 24 may become fast. And, the condensation liquid water is discharged out of the system by the gas stream of the large flowing velocity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、イオン交換膜を適度の湿潤状態に維持しながら電池内から系外に水分を排出する固体高分子型燃料電池用セパレータに関する。   The present invention relates to a polymer electrolyte fuel cell separator that discharges moisture from the inside of the battery to the outside of the system while maintaining the ion exchange membrane in a moderately wet state.

固体高分子型燃料電池は、環境に及ぼす影響が少なく、室温程度の低温でも起動・発電できる長所から自動車の動力源，家庭用電源等、各種分野で可動型又は定置型電気エネルギー供給源として期待されている。固体高分子型燃料電池は、高分子イオン交換膜１１の両面に触媒電極層１２，１３を形成し、ガス拡散層１４，１５で挟んだ膜-電極接合体１０で構成されている（図１）。
触媒電極層１２（燃料極）側にＨ2含有燃料を送り込むと、燃料極１２上でＨ2がプロトンＨ+となる。プロトンＨ+は、水の存在下で高分子イオン交換膜１１を透過して触媒電極層１３（酸化極）に移動し、酸化極１３側に送り込まれてきた酸化剤中のＯ2及び外部回路１６から流れてきた電子ｅ-と反応し、水（反応生成水）として系外に排出される。外部回路１６に沿った電子ｅ-の流れが電気エネルギーとして取り出されるが、単体の膜-電極接合体１０から取り出される電気量は極僅かである。そこで、多数の膜-電極接合体１０をスタックすることにより、実用に供せられる電力を得ている。 Solid polymer fuel cells have little impact on the environment and are expected to be movable or stationary electric energy sources in various fields such as automobile power sources and household power sources due to their advantages of starting and generating power even at low temperatures around room temperature. Has been. The polymer electrolyte fuel cell includes a membrane-electrode assembly 10 in which catalyst electrode layers 12 and 13 are formed on both surfaces of a polymer ion exchange membrane 11 and sandwiched between gas diffusion layers 14 and 15 (FIG. 1). ).
When the H 2 -containing fuel is fed to the catalyst electrode layer 12 (fuel electrode) side, H 2 becomes proton H + on the fuel electrode 12. Proton H + permeates the polymer ion exchange membrane 11 in the presence of water, moves to the catalyst electrode layer 13 (oxidation electrode), and O 2 in the oxidant that has been sent to the oxidation electrode 13 side and an external circuit. It reacts with the electron e − flowing from 16 and is discharged out of the system as water (reaction product water). The flow of electrons e − along the external circuit 16 is extracted as electric energy, but the amount of electricity extracted from the single membrane-electrode assembly 10 is very small. Therefore, by stacking a large number of membrane-electrode assemblies 10, electric power for practical use is obtained.

膜-電極接合体１０は、セパレータを介してスタックされる。導電性，耐食性が要求されるセパレータは、カーボンブロックを切り出し切削加工することにより作製されているが、導電性を改善したステンレス鋼等の耐食性金属材料を素材とすることも検討されている。セパレータには、ガス拡散層１４，１５を介して燃料ガス，酸化剤ガスを触媒電極層１２，１３に供給するガス流路が形成されており、ガス流路形状に関する種々の改良が提案されている。たとえば、燃料ガス，酸化剤ガスの入側流路，出側流路を互いに分離し、櫛歯状に組み合わせると、触媒電極層１２，１３に満遍なく燃料ガス，酸化剤ガスが分配され、電池性能が向上する（特許文献１）。
特開平11-16591号公報 The membrane-electrode assembly 10 is stacked via a separator. A separator that requires electrical conductivity and corrosion resistance is manufactured by cutting out and cutting a carbon block. However, it is also considered to use a corrosion-resistant metal material such as stainless steel with improved electrical conductivity as a raw material. The separator is formed with a gas flow path for supplying fuel gas and oxidant gas to the catalyst electrode layers 12 and 13 through the gas diffusion layers 14 and 15, and various improvements regarding the gas flow path shape have been proposed. Yes. For example, when the inlet and outlet channels of fuel gas and oxidant gas are separated from each other and combined in a comb shape, the fuel gas and oxidant gas are evenly distributed to the catalyst electrode layers 12 and 13, and the battery performance (Patent document 1).
Japanese Patent Laid-Open No. 11-16591

電池反応に消費された分を除く燃料ガス，酸化剤ガスが出側流路を経て系外に排出され、電池反応で生成した水も同じ出側流路を経て系外に排出される。燃料電池の運転を停止する場合、燃料ガス，酸化剤ガスの供給を止めるが、余剰の燃料ガス，酸化剤ガスや反応生成水が系外に排出されず電池内に残る。高分子イオン交換膜１１の伝導性を確保するため燃料ガス，酸化剤ガスを加湿して使用することもあり、この場合には電池内に残留している燃料ガス，酸化剤ガスから結露水が生じる。   Fuel gas and oxidant gas excluding the amount consumed in the battery reaction are discharged out of the system through the outlet channel, and water generated by the battery reaction is also discharged out of the system through the same outlet channel. When stopping the operation of the fuel cell, the supply of the fuel gas and the oxidant gas is stopped, but the surplus fuel gas, the oxidant gas and the reaction product water remain in the cell without being discharged out of the system. In order to ensure the conductivity of the polymer ion exchange membrane 11, the fuel gas and the oxidant gas may be used in a humidified state. In this case, the dew condensation water is generated from the fuel gas and the oxidant gas remaining in the battery. Arise.

燃料電池では、急激な負荷の変動や運転・停止操作によってガス消費量，セルの発熱量が大きく変動するので、セル内で結露水の発生及び乾燥が起きやすくなる。結露水の存在下で高分子イオン交換膜１１が分解すると、分解に伴って発生するフッ素イオンが結露水に溶け込み腐食性の溶液となる。引き続く水分の蒸発によりフッ素イオンが濃化すると、結露水の腐食性が強くなる。濃化した結露水が金属セパレータを溶解すると、溶出した金属イオンが高分子イオン交換膜１１に侵入してイオン伝導性を低下させ、燃料電池の発電効率が下がる。   In the fuel cell, the gas consumption and the heat generation amount of the cell greatly fluctuate due to a sudden load change and operation / stop operation, so that the generation and drying of the condensed water easily occur in the cell. When the polymer ion exchange membrane 11 is decomposed in the presence of condensed water, the fluorine ions generated along with the decomposition are dissolved in the condensed water to form a corrosive solution. When fluorine ions are concentrated by the subsequent evaporation of moisture, the corrosiveness of the condensed water becomes stronger. When the condensed condensed water dissolves the metal separator, the eluted metal ions enter the polymer ion exchange membrane 11 to lower the ion conductivity, and the power generation efficiency of the fuel cell is lowered.

結露水を系外に排出する機能を備えたガス流路を形成するとき、金属製セパレータの腐食を抑え、長期にわたり発電効率が高位に安定することが予想される。ところが、入側流路，出側流路を独立させたガス流路は、燃料ガス，酸化剤ガスをガス拡散層１４，１５で拡散させて触媒電極層１２，１３に接触させることを前提にし、電池内に残留する結露水に起因する悪影響を考慮していない。却って、入側流路の先端が閉じられており、結露水が溜まり易い形状になっている。
本発明は、フッ素を溶かし込んだ結露水が金属製セパレータを溶解し、燃料電池の発電効率を低下させることを考慮し、結露水が系外に排出されやすい形状のガス流路を形成することにより、長期にわたり良好な発電効率を維持する固体高分子型燃料電池を提供することを目的とする。 When forming a gas flow path having a function of discharging condensed water out of the system, it is expected that the corrosion of the metal separator is suppressed and the power generation efficiency is stabilized at a high level over a long period of time. However, the gas flow path in which the inlet flow path and the outlet flow path are made independent is based on the premise that the fuel gas and the oxidant gas are diffused in the gas diffusion layers 14 and 15 and brought into contact with the catalyst electrode layers 12 and 13. The adverse effects caused by the dew condensation water remaining in the battery are not taken into consideration. On the other hand, the front end of the inlet-side flow path is closed, so that the condensed water tends to accumulate.
In consideration of the fact that dew condensation water in which fluorine is dissolved dissolves the metal separator and lowers the power generation efficiency of the fuel cell, the present invention forms a gas flow path having a shape in which dew condensation water is easily discharged out of the system. Thus, an object of the present invention is to provide a polymer electrolyte fuel cell that maintains good power generation efficiency over a long period of time.

本発明は、複数の膜-電極接合体をセパレータを介してスタックすることにより電力を取り出す構造の固体高分子型燃料電池において、複数の分岐路が互いに櫛歯状に噛み合う入側流路，出側流路をセパレータに形成し、入側流路の分岐路を排水溝を介して出側流路の集合部に連通させている。排水溝の断面積は、入側流路の分岐路より小さくすることが好ましい。出側流路の分岐路も、排水溝を介して入側流路の集合部に連通させても良い。   The present invention provides a polymer electrolyte fuel cell having a structure in which electric power is taken out by stacking a plurality of membrane-electrode assemblies through separators. The side flow path is formed in the separator, and the branch path of the input side flow path is communicated with the collecting portion of the output side flow path through the drainage groove. The cross-sectional area of the drainage groove is preferably smaller than the branch path of the inlet side flow path. The branch channel of the outlet side channel may also be communicated with the collecting portion of the inlet side channel via the drainage groove.

本発明に従ったセパレータは、燃料ガス，酸化剤ガスを電池内に送り込む入側流路２０及び余剰の燃料ガス，酸化剤ガス及び反応生成水を系外に排出する出側流路３０を備えている（図２）。入側流路２０，出側流路３０を分離しているので、入側流路２０から送り込まれる燃料ガス，酸化剤ガスは、流出ガスが流入ガスの抵抗にならず実質的に大半がガス拡散層１４，１５に拡散して触媒電極層１２，１３と接触した後、出側流路３０を経て系外に排出される。   The separator according to the present invention includes an inlet-side passage 20 for sending fuel gas and oxidant gas into the battery, and an outlet-side passage 30 for discharging excess fuel gas, oxidant gas and reaction product water out of the system. (FIG. 2). Since the inlet-side channel 20 and the outlet-side channel 30 are separated, the fuel gas and the oxidant gas fed from the inlet-side channel 20 are substantially out of the resistance of the inflow gas. After diffusing into the diffusion layers 14 and 15 and coming into contact with the catalyst electrode layers 12 and 13, they are discharged out of the system through the outlet side flow path 30.

入側流路２０は、ガス入口２１に連なる集合部２２から複数の分岐路２３が櫛歯状に延びている。出側流路３０も同様な櫛歯状になっており、ガス出口３１に連なる集合部３２に複数の分岐路３３を集約させている。分岐路２３，３３が互いに噛み合う配置で入側流路２０，出側流路３０を設計することにより、入側流路２０から燃料ガス，酸化剤ガスがガス拡散層１４，１５を介して触媒電極層１２，１３に満遍なく供給され、電池反応に消費された後、出側流路３０を経て系外に排出される。
加湿した燃料ガスや酸化剤ガスを燃料電池に送り込むとき、電池内部に結露水が生じ易くなる。電池内には、電池反応で生成した水もある。本発明では、反応生成水を含む結露水の排出を促進させるため、排水溝２４を介して分岐路２３を集合部３２に連通させている。出側流路３０の分岐路３３も、必要に応じ排水溝３４を介して集合部２２に連通させても良い。 In the inlet-side flow path 20, a plurality of branch paths 23 extend in a comb-like shape from a collecting portion 22 that is continuous with the gas inlet 21. The outlet side flow path 30 has a similar comb-teeth shape, and a plurality of branch paths 33 are aggregated in a collecting portion 32 connected to the gas outlet 31. By designing the inlet-side channel 20 and the outlet-side channel 30 in such a manner that the branch paths 23 and 33 mesh with each other, fuel gas and oxidant gas are passed from the inlet-side channel 20 via the gas diffusion layers 14 and 15. After being uniformly supplied to the electrode layers 12 and 13 and consumed in the battery reaction, it is discharged out of the system through the outlet side flow path 30.
When humidified fuel gas or oxidant gas is sent to the fuel cell, dew condensation water tends to be generated inside the cell. There is also water produced by the battery reaction in the battery. In the present invention, the branch path 23 is communicated with the collecting portion 32 through the drainage groove 24 in order to promote the discharge of the dew condensation water containing the reaction product water. The branch channel 33 of the outlet channel 30 may be communicated with the collecting portion 22 through the drainage groove 34 as necessary.

排水溝２４は、分岐路２３より幅を狭め（図３a）、或いは分岐路２３より浅くする（図３b）ことにより断面積を小さくしている。たとえば、幅：２ｍｍ，深さ：２ｍｍの分岐路２３に対して排水溝２４の幅を１.０〜２.０ｍｍ，深さを０.５〜１.０ｍｍに設定し、排水溝２４／分岐路２３の段面積比率を１／２〜１／８の範囲に調整することが好ましい。小断面積の排水溝２４は流路抵抗が大きいので、送り込まれた燃料ガス，酸化剤ガスの大半がガス拡散層１４，１５に拡散し電池反応に供される。   The drainage groove 24 has a smaller cross-sectional area by making it narrower than the branch path 23 (FIG. 3a) or shallower than the branch path 23 (FIG. 3b). For example, the width of the drainage groove 24 is set to 1.0 to 2.0 mm and the depth is set to 0.5 to 1.0 mm with respect to the branch path 23 having a width of 2 mm and a depth of 2 mm. It is preferable to adjust the step area ratio of the path 23 to a range of 1/2 to 1/8. Since the drainage groove 24 having a small cross-sectional area has a large flow path resistance, most of the fed fuel gas and oxidant gas diffuse into the gas diffusion layers 14 and 15 and are used for the cell reaction.

分岐路２３から集合部３２に向けて排水溝２４内を流れる燃料ガス，酸化剤ガスもあるが、排水溝２４の断面積が小さいため流速が大きくなる。分岐路２３の内壁ガス拡散層１４，１５内部に付着している結露水は、大流速のガス流によって分岐路２３から集合部３２に運ばれる。ガス拡散層１４，１５の内部にある結露水も、ガス流による吸引作用で集合部３２に送り込まれる。その結果、入側流路２０に留まる結露水が殆どなくなる。
分岐路３３を集合部２２に連通させる排水溝３４を設けた場合でも、結露水が溜まり易い分岐路３３の先端部分に大流速のガス流が排水溝３４から流入するので、分岐路３３の内壁に付着している結露水は燃料ガス，酸化剤ガスのガス流によって持ち去られる。 Although there are fuel gas and oxidant gas flowing in the drainage groove 24 from the branch path 23 toward the collecting portion 32, the flow velocity increases because the sectional area of the drainage groove 24 is small. Condensed water adhering to the inside of the inner wall gas diffusion layers 14 and 15 of the branch path 23 is carried from the branch path 23 to the collecting portion 32 by a gas flow at a high flow rate. Condensed water in the gas diffusion layers 14 and 15 is also sent into the collecting portion 32 by the suction action by the gas flow. As a result, almost no condensed water remains in the inlet-side flow path 20.
Even in the case where the drainage groove 34 that allows the branch path 33 to communicate with the collecting portion 22 is provided, a high-velocity gas flow flows from the drainage groove 34 into the tip of the branch path 33 where condensed water tends to accumulate. Condensed water adhering to the fuel is carried away by the flow of fuel gas and oxidant gas.

このように、入側流路２０→ガス拡散層１４，１５→出側流路３０にガス流路を設定しているので、ガス拡散層１４，１５を通して十分な量の燃料ガス，酸化剤ガスを触媒電極層１２，１３に供給できる。特に酸化極１３側では、酸化剤ガスと向流状態にある生成水がスムーズに排出され、酸化剤ガスの十分な供給・拡散が図られるため、拡散分極も抑制される。結露した場合でも、入側流路２０の分岐路２３が断面積の小さな排水溝２４で出側流路３０の集合部３２に連通しているので、ガス拡散を妨害する結露水の滞留が抑制される。高分子イオン交換膜１１が分解して腐食性ガスが発生する場合でも、セパレータの腐食及び結露水への重金属イオンの溶込みが出側流路に限られるため、重金属イオンは高分子イオン交換膜１１に触れることなく排出される。その結果、重金属イオンによる高分子イオン交換膜１１の汚染が大幅に抑制され、長期にわたり燃料電池の発電能力が高位に安定する。   Thus, since the gas flow path is set from the inlet side flow path 20 → the gas diffusion layer 14, 15 → the outlet side flow path 30, a sufficient amount of fuel gas and oxidant gas are passed through the gas diffusion layers 14 and 15. Can be supplied to the catalyst electrode layers 12 and 13. In particular, on the oxidation electrode 13 side, the generated water in a counter-current state with the oxidant gas is smoothly discharged and sufficient supply / diffusion of the oxidant gas is achieved, so that diffusion polarization is also suppressed. Even when condensation occurs, the branching path 23 of the inlet-side channel 20 communicates with the collecting portion 32 of the outlet-side channel 30 through a drainage groove 24 having a small cross-sectional area, so that retention of condensed water that hinders gas diffusion is suppressed. Is done. Even when the polymer ion exchange membrane 11 is decomposed and corrosive gas is generated, the corrosion of the separator and the penetration of heavy metal ions into the dew condensation water are limited to the outlet channel, so that the heavy metal ions are polymer ion exchange membranes. 11 is discharged without touching. As a result, the contamination of the polymer ion exchange membrane 11 by heavy metal ions is greatly suppressed, and the power generation capability of the fuel cell is stabilized at a high level for a long time.

板厚：３ｍｍのSUS430ステンレス鋼板を１２０ｍｍ×１２０ｍｍのサイズに裁断し、入側流路２０，出側流路３０を成形した。入側流路２０，出側流路３０共に、幅：３ｍｍ，深さ：２ｍｍの集合部２２，３２から幅：１ｍｍ，深さ：２ｍｍ，長さ：４９ｍｍの分岐路２３，３３が６ｍｍの等間隔で９本分かれた形状とした。分岐路２３，３３は、先端に形成した幅：１ｍｍ，深さ：０.５ｍｍ，長さ：２ｍｍの排水溝２４，３４で集合部３２，２２に連通させた。   Plate thickness: A SUS430 stainless steel plate having a thickness of 3 mm was cut into a size of 120 mm × 120 mm, and the inlet-side channel 20 and the outlet-side channel 30 were formed. Both the inlet-side channel 20 and the outlet-side channel 30 have a width: 3 mm, a depth: 2 mm from the collecting portions 22, 32, a width: 1 mm, a depth: 2 mm, and a length: 49 mm. The shape was divided into nine at equal intervals. The branch paths 23 and 33 are communicated with the collecting portions 32 and 22 through drain grooves 24 and 34 having a width of 1 mm, a depth of 0.5 mm, and a length of 2 mm formed at the tip.

カーボンペーパ（TGP-H-120：東レ株式会社製）に白金触媒をコーティングした電極を高分子イオン交換膜（ナフィオン１１５：デュポン社製）にホットプレスで接合することにより作製した反応面積２５ｃｍ2の膜-電極接合体１０にセパレータを挟んで燃料電池を組み立てた。
加湿した水素ガス，酸素ガスを共に０.５リットル／分の流量で送り込み、出側圧力を常圧とし、電子負荷装置で出力を調整しながら燃料電池を電流密度０.５Ａ／ｃｍ2で定電流運転した。運転開始直後のセル電圧は０.７Ｖであり、８時間連続運転→１６時間運転停止を２０サイクル繰り返した後でも０.７Ｖのセル電圧であった。
サイクル試験後に燃料電池を解体してセパレータを取り出し、セパレータの表面状態を観察したところ腐食が検出されなかった。また、接触抵抗も２００ｍΩ・ｃｍ2であり、未使用セパレータに比較して接触抵抗の大幅な増加がみられなかった。 A reaction area of 25 cm 2 produced by joining a carbon paper (TGP-H-120: manufactured by Toray Industries, Inc.) with an electrode coated with a platinum catalyst to a polymer ion exchange membrane (Nafion 115: manufactured by DuPont) by hot pressing. A fuel cell was assembled with a separator sandwiched between the membrane-electrode assembly 10.
Humidified hydrogen gas and oxygen gas are fed at a flow rate of 0.5 liters / minute, the outlet side pressure is set to normal pressure, and the output is adjusted by an electronic load device, and the fuel cell is fixed at a current density of 0.5 A / cm 2 . Current driving. The cell voltage immediately after the start of operation was 0.7 V, and the cell voltage was 0.7 V even after 20 cycles of continuous operation for 8 hours → stop operation for 16 hours.
After the cycle test, the fuel cell was disassembled, the separator was taken out, and when the surface condition of the separator was observed, no corrosion was detected. Further, the contact resistance was 200 mΩ · cm 2 , and no significant increase in contact resistance was observed compared to the unused separator.

比較のため、分岐路２３，３３を集合部３２，２２に連通する排水溝２４，３４がないことを除き同様な入側流路２０，出側流路３０を形成したセパレータを組み込んだ燃料電池について、同じ条件下で運転試験したところ、運転開始直後に０.７Ｖであったセル電圧が８時間連続運転→１６時間運転停止を２０サイクル繰り返した後で０.４５Ｖまで降下した。燃料電池を解体して取り出したセパレータを観察した結果、分岐路２３，３３の先端近傍に腐食が検出され、特に酸化極１３側では著しい腐食が発生していた。
この対比から、小断面積の排水溝２４，３４で分岐路２３，３３を集合部３２，２２に連通させることにより、入側流路２０，出側流路３０を分離したセパレータで生じがちな結露水の滞留が防止され、電池内の腐食性雰囲気を緩和できる。その結果、金属製セパレータにあっては腐食による接触抵抗の増加が抑えられ、送り込まれる燃料ガス，酸化剤ガスが電池反応に効率よく消費されることと相まって発電効率が高い固体高分子型燃料電池となる。 For comparison, a fuel cell incorporating a separator having the same inlet-side channel 20 and outlet-side channel 30 except that there are no drainage grooves 24, 34 that connect the branch channels 23, 33 to the collecting portions 32, 22. When the operation test was conducted under the same conditions, the cell voltage, which was 0.7 V immediately after the start of operation, dropped to 0.45 V after 20 cycles of continuous operation for 16 hours → stop operation for 16 hours. As a result of observing the separator taken out by disassembling the fuel cell, corrosion was detected in the vicinity of the ends of the branch paths 23 and 33, and significant corrosion occurred particularly on the oxidation electrode 13 side.
From this comparison, by connecting the branch passages 23 and 33 to the collecting portions 32 and 22 through the drain grooves 24 and 34 having a small cross-sectional area, the separator is likely to be generated in the inlet-side channel 20 and the outlet-side channel 30. The retention of condensed water is prevented, and the corrosive atmosphere in the battery can be relaxed. As a result, in the case of a metal separator, an increase in contact resistance due to corrosion is suppressed, and a solid polymer fuel cell with high power generation efficiency coupled with efficient consumption of fuel gas and oxidant gas fed into the cell reaction It becomes.

以上に説明したように、入側流路２０，出側流路３０を分離したセパレータで膜-電極接合体１０を挟み込んで燃料電池を構築するとき、送り込まれる燃料ガス，酸化剤ガスのほぼ全量がガス拡散層１４，１５を拡散して触媒電極層１２，１３に送られるため、電池反応に消費される燃料ガス，酸化剤ガスの割合が高くなる。また、小断面積の排水溝２４を介して入側流路２０の分岐路２３を出側流路３０の集合部３２に連通させているので、電池内の結露水がガス流に乗って系外に排出され、結露水に含まれている重金属イオンによる高分子イオン交換膜１１の汚染が抑えられ、電池内の腐食性雰囲気が緩和される。その結果、金属製セパレータを使用した燃料電池では接触抵抗の増加が抑えられ、発電効率が高位に安定する。   As described above, when the fuel cell is constructed by sandwiching the membrane-electrode assembly 10 with the separator separated from the inlet-side channel 20 and the outlet-side channel 30, almost all of the fuel gas and oxidant gas to be sent Diffuses through the gas diffusion layers 14 and 15 and is sent to the catalyst electrode layers 12 and 13, so that the ratio of the fuel gas and the oxidant gas consumed in the cell reaction increases. In addition, since the branch path 23 of the inlet-side channel 20 is communicated with the collecting portion 32 of the outlet-side channel 30 through the drainage groove 24 having a small cross-sectional area, the condensed water in the battery rides on the gas flow. Contamination of the polymer ion exchange membrane 11 by heavy metal ions discharged to the outside and contained in the dew condensation water is suppressed, and the corrosive atmosphere in the battery is alleviated. As a result, in a fuel cell using a metal separator, an increase in contact resistance is suppressed, and power generation efficiency is stabilized at a high level.

固体高分子型燃料電池の内部構造を示す概略図Schematic showing the internal structure of a polymer electrolyte fuel cell 分岐路が櫛歯状に噛み合った入側流路，出側流路を形成したセパレータの平面図A plan view of a separator having an inlet-side channel and an outlet-side channel in which the branch path meshes in a comb shape. 入側流路の分岐路が排水溝を介して出側流路の集合部に連通していることを示す部分平面図（a），部分断面図（b）Partial plan view (a) and partial cross-sectional view (b) showing that the branching path of the inlet channel communicates with the collecting part of the outlet channel through the drainage groove

符号の説明Explanation of symbols

１０：膜-電極接合体 １１：高分子イオン交換膜 １２：触媒電極層（燃料極） １３：触媒電極層（酸化極） １４，１５：ガス拡散層 １６：外部回路
２０：入側流路 ３０：出側流路 ２１：ガス入口 ３１：ガス出口 ２２，３２：集合部 ２３，３３：分岐路 ２４，３４：排水溝 10: Membrane-electrode assembly 11: Polymer ion exchange membrane 12: Catalyst electrode layer (fuel electrode) 13: Catalyst electrode layer (oxidation electrode) 14, 15: Gas diffusion layer 16: External circuit 20: Inlet channel 30 : Outlet channel 21: Gas inlet 31: Gas outlet 22, 32: Collecting part 23, 33: Branch 24, 34: Drainage channel

Claims (3)

複数の膜-電極接合体の間に介装されるセパレータであり、入側流路，出側流路が互いに噛み合う複数の櫛歯状分岐路をもち、入側流路の分岐路先端が排水溝を介して出側流路の集合部に連通していることを特徴とする固体高分子型燃料電池用セパレータ。   A separator interposed between a plurality of membrane-electrode assemblies, which has a plurality of comb-like branching channels in which the inlet and outlet channels mesh with each other, and the leading end of the branching channel of the inlet channel drains A separator for a polymer electrolyte fuel cell, characterized in that it communicates with a collecting portion of an outlet-side flow path through a groove. 入側流路の分岐路より小さな断面積で排水溝が形成されている請求項１記載の固体高分子型燃料電池用セパレータ。   The separator for a polymer electrolyte fuel cell according to claim 1, wherein the drainage groove is formed with a smaller cross-sectional area than the branch channel of the inlet side channel. 更に、出側流路の櫛歯状分岐路が排水溝を介して入側流路の集合部に連通している請求項１記載の固体高分子型燃料電池用セパレータ。   2. The polymer electrolyte fuel cell separator according to claim 1, wherein the comb-like branching path of the outlet side channel communicates with the collecting portion of the inlet side channel via the drainage groove.
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Cited By (9)

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Publication number Priority date Publication date Assignee Title
JP2006114387A (en) * 2004-10-15 2006-04-27 Toyota Motor Corp Fuel cell
JP2007265939A (en) * 2006-03-30 2007-10-11 Ngk Insulators Ltd Electrochemical device
JP2008171608A (en) * 2007-01-10 2008-07-24 Sharp Corp Fuel cell
JP2009059685A (en) * 2007-08-07 2009-03-19 Honda Motor Co Ltd Fuel cell
US8221930B2 (en) 2006-08-23 2012-07-17 Daimler Ag Bipolar separators with improved fluid distribution
US8568941B2 (en) 2009-03-04 2013-10-29 Panasonic Corporation Fuel cell separator and fuel cell including same
US8921000B2 (en) 2010-07-15 2014-12-30 Toyota Jidosha Kabushiki Kaisha Fuel cell
JP2018097977A (en) * 2016-12-09 2018-06-21 トヨタ自動車株式会社 Fuel cell separator and fuel cell
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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006114387A (en) * 2004-10-15 2006-04-27 Toyota Motor Corp Fuel cell
JP2007265939A (en) * 2006-03-30 2007-10-11 Ngk Insulators Ltd Electrochemical device
US8221930B2 (en) 2006-08-23 2012-07-17 Daimler Ag Bipolar separators with improved fluid distribution
JP2008171608A (en) * 2007-01-10 2008-07-24 Sharp Corp Fuel cell
JP2009059685A (en) * 2007-08-07 2009-03-19 Honda Motor Co Ltd Fuel cell
US8568941B2 (en) 2009-03-04 2013-10-29 Panasonic Corporation Fuel cell separator and fuel cell including same
US8921000B2 (en) 2010-07-15 2014-12-30 Toyota Jidosha Kabushiki Kaisha Fuel cell
JP2018097977A (en) * 2016-12-09 2018-06-21 トヨタ自動車株式会社 Fuel cell separator and fuel cell
US11450862B2 (en) 2016-12-09 2022-09-20 Toyota Jidosha Kabushiki Kaisha Separator for fuel cell and fuel cell
DE102017127492B4 (en) 2016-12-09 2023-07-20 Toyota Jidosha Kabushiki Kaisha SEPARATION DEVICE FOR FUEL CELL AND FUEL CELL
JP2022502822A (en) * 2018-11-16 2022-01-11 上海恒勁動力科技有限公司 Fuel cell guidance baffle
JP7079996B2 (en) 2018-11-16 2022-06-03 上海恒勁動力科技有限公司 Fuel cell guidance baffle

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