JPH08250132A - Phosphoric acid type fuel cell - Google Patents

Abstract

PURPOSE: To provide a phosphoric acid type fuel cell capable of smoothly moving phosphoric acid between an oxidant electrode side reservoir and a matrix without causing the diffusion failure of an oxidant. CONSTITUTION: A unit cell 20 is provided with a matrix 2 preserving phosphoric acid in a porous unconductive base material, fuel and oxidant electrodes 3 and 4 nipping the matrix to be layered on both the sides of the matrix, and reservoir plates 21 and 22, composed of a hydrophilic rib-attached porous carbon base material, wherein a rib portion 7 is closely adhered to the fuel and oxidant electrodes to form a reaction gas passage 8. In this phosphoric acid type fuel cell, plural layers of this cell 20 are layered with separation plates 9 interposed. At least the electrode 4 of a pair of these electrodes is composed of an electrode base material 27 composed of a porous carbon plate previously water-treated, and an electrode catalytic layer 5; and a phosphoric acid movement path part 23, composed of a porous member nipped by the matrix and the reservoir plates, is provided on at least part of the peripheral part of this oxidant electrode.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】この発明は、例えばりん酸を電解
質とするりん酸型燃料電池、ことにマトリックス中のり
ん酸量を安定して保持するリザーバーを備えたりん酸型
燃料電池に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphoric acid fuel cell using, for example, phosphoric acid as an electrolyte, and more particularly to a phosphoric acid fuel cell having a reservoir for stably holding the amount of phosphoric acid in a matrix.

【０００２】[0002]

【従来の技術】図３はリブ付電極方式のりん酸型燃料電
池の従来の単位セルを展開して示す斜視図であり、単位
セル１は電解質としてのりん酸を保持した電解質層（マ
トリックスと呼ぶ）２を挟んでその両側に燃料電極３お
よび酸化剤電極（空気電極）４を配した構造となってい
る。また、燃料電極３および酸化剤電極４はそれぞれ白
金などの電極触媒を担持した電極触媒層５と、ガス透過
性を有する多孔質炭素板からなるリブ付き電極基材６と
の積層体からなり、リブ付き電極基材６の反電極触媒層
側には互いに間隔を置いて平行かつ凸に形成された複数
のリブ７が形成され、互いに隣接するリブ７の間にはコ
字状に形成された複数の反応ガス供給溝（反応ガス通路
とも呼ぶ）８が形成される。2. Description of the Related Art FIG. 3 is an exploded perspective view showing a conventional unit cell of a ribbed electrode type phosphoric acid fuel cell. The unit cell 1 is an electrolyte layer (a matrix and a matrix) holding phosphoric acid as an electrolyte. 2) is sandwiched between the fuel electrode 3 and the oxidizer electrode (air electrode) 4. Each of the fuel electrode 3 and the oxidant electrode 4 is a laminate of an electrode catalyst layer 5 carrying an electrode catalyst such as platinum and a ribbed electrode substrate 6 made of a porous carbon plate having gas permeability, On the side of the electrode base material 6 with ribs opposite to the electrode catalyst layer, a plurality of parallel and convex ribs 7 are formed at intervals, and the ribs 7 adjacent to each other are formed in a U shape. A plurality of reaction gas supply grooves (also called reaction gas passages) 8 are formed.

【０００３】このように構成された単位セル１は、反応
ガス供給溝８の向きが燃料電極３と酸化剤電極４とで互
いに直交するようマトリックス２を挟んで積層されると
ともに、隣接する単位セル１間にガス不透過性炭素板か
らなる平板状のセパレ−ト板９を配して複数層積層する
ことにより、所望の出力電圧を有する積層燃料電池（ス
タック）が構成される。In the unit cell 1 thus constructed, the matrix 2 is sandwiched so that the reaction gas supply grooves 8 are orthogonal to each other in the fuel electrode 3 and the oxidizer electrode 4. A flat fuel cell (stack) having a desired output voltage is formed by arranging a flat plate-shaped separator plate 9 made of a gas impermeable carbon plate between the two and stacking a plurality of layers.

【０００４】リブ付き電極基材６はカ−ボン繊維にバイ
ンダを加えてリブ７を有する厚紙状に成形し、これを焼
成した後、フッ素樹脂〔ポリテトラフルオロエチレン
（ＰＴＦＥ）等〕を含む処理液を含浸，焼成処理しては
っ水処理したものからなり、電極基材６には平均空孔径
が５０μｍ程度の細孔が一定の気孔率で一様に分布して
形成される。従って、燃料電極３のリブ付き電極基材６
では反応ガス供給溝８を通る燃料ガス中の水素が基材６
の微細な細孔を透過して電極触媒層５に供給され、酸化
剤電極４側の電極基材６では反応ガス供給溝８を通る酸
化剤としての空気中の酸素が細孔を透過して電極触媒層
５に供給されることにより、供給された反応ガス中の活
物質が電極触媒粒子の表面で電解質と接触することによ
り電気化学反応に基づく発電が行われる。また、リブ付
き電極基材６をはっ水処理しておくことにより、電解質
で濡れた電極触媒粒子を保持する電極触媒層５から電解
質がしみ出して電極基材６側に浸透し、空孔を閉塞して
電極触媒層への反応ガスの供給を阻害することを防ぐこ
とができる。The electrode base material 6 with ribs is formed by adding a binder to carbon fiber to form a cardboard having the ribs 7, firing this, and then treating it with a fluororesin [polytetrafluoroethylene (PTFE) or the like]. The electrode base material 6 is formed by impregnation with a liquid, firing treatment and water repellent treatment, and pores having an average pore diameter of about 50 μm are uniformly distributed with a constant porosity. Therefore, the ribbed electrode substrate 6 of the fuel electrode 3
Then, hydrogen contained in the fuel gas passing through the reaction gas supply groove 8 is the base material 6
Of oxygen in the air as an oxidant passing through the reaction gas supply groove 8 in the electrode base material 6 on the side of the oxidizer electrode 4 permeate through the pores. By being supplied to the electrode catalyst layer 5, the active material in the supplied reaction gas comes into contact with the electrolyte on the surface of the electrode catalyst particles, so that power generation based on the electrochemical reaction is performed. Further, by subjecting the ribbed electrode base material 6 to a water repellent treatment, the electrolyte seeps out from the electrode catalyst layer 5 holding the electrode catalyst particles wet with the electrolyte and permeates to the electrode base material 6 side to form pores. It is possible to prevent the supply of the reaction gas to the electrode catalyst layer from being obstructed by blocking the above.

【０００５】上述のように構成された燃料電池の従来の
単位セル１において、その発電反応は水素と酸素が反応
して水と電子を生成する反応であり、例えばりん酸型燃
料電池の場合１９０°C 程度の運転温度を保持して運転
されることにより、酸化剤電極４側の電極触媒層５で生
成した水が水蒸気となって電極基材６を透過して反応ガ
ス通路８内に放出され、反応を終わったオフガスととも
に系外に排出される。このとき、電極触媒層５で生成し
た水が水蒸気化する際、微量のりん酸を巻き込んだ状態
でリブ付き電極基材６を透過して反応ガス通路８に放出
されるため、マトリックス２が保持するりん酸が徐々に
減少し、これが原因で燃料電池の内部抵抗が上昇して出
力電圧が低下するとともに、遂には反応ガスが直接反応
して電池を損傷するという事態に進展する可能性があ
る。また、燃料電池の運転温度の変化や水蒸気分圧条件
の変化によってりん酸体積が変化し、膨張したりん酸が
リブ付き電極基材６の細孔内に侵出して細孔を塞ぐた
め、これに伴って電極基材の気孔率および有効拡散係数
が低下して電極触媒層への反応活物質の供給が不足して
反応ガスの供給障害が発生し、遂には単位セルの出力電
圧の低下を招くという問題がある。そこで、電解質の飛
散によりマトリックス中で不足する電解質を補給し、ま
たマトリックス中の電解質の体積変化を吸収するため
に、電解質を溜めるリザーバーを単位セル内に設けた燃
料電池が知られており、また、リザーバーとマトリック
スの間の電解質の移動経路について幾つかのアイデアが
提案されている。In the conventional unit cell 1 of the fuel cell constructed as described above, the power generation reaction is a reaction in which hydrogen and oxygen react to generate water and electrons. For example, in the case of a phosphoric acid fuel cell, 190 By operating at an operating temperature of about ° C, the water generated in the electrode catalyst layer 5 on the oxidizer electrode 4 side becomes water vapor and permeates the electrode base material 6 and is discharged into the reaction gas passage 8. Is discharged to the outside of the system together with the off gas that has finished the reaction. At this time, when the water generated in the electrode catalyst layer 5 is vaporized, a slight amount of phosphoric acid is passed through the ribbed electrode base material 6 and released into the reaction gas passage 8, so that the matrix 2 is retained. There is a possibility that the amount of phosphoric acid will gradually decrease, which causes the internal resistance of the fuel cell to rise and the output voltage to drop, and eventually the reaction gas to react directly and damage the cell. . Further, the volume of phosphoric acid changes due to changes in the operating temperature of the fuel cell and changes in the partial pressure of water vapor, and the expanded phosphoric acid invades into the pores of the ribbed electrode substrate 6 to close the pores. Accompanying this, the porosity and effective diffusion coefficient of the electrode base material decrease, and the supply of the reaction active material to the electrode catalyst layer becomes insufficient, causing a reaction gas supply failure, and eventually the output voltage of the unit cell decreases. There is a problem of inviting. Therefore, in order to replenish the electrolyte lacking in the matrix due to the scattering of the electrolyte and to absorb the volume change of the electrolyte in the matrix, a fuel cell in which a reservoir for storing the electrolyte is provided in the unit cell is known, and , Several ideas have been proposed for the route of movement of the electrolyte between the reservoir and the matrix.

【０００６】例えば、リブ付き電極基材６の一部に親水
性の部分を設け、この親水性の部分を電解質を溜め込む
リザーバーとして利用することにより、反応ガスの供給
障害を生ずることなく電解質の飛散によりマトリックス
中で不足する電解質量を補給し、またマトリックス中の
電解質の体積変化を吸収するようにした燃料電池が特開
昭６１−１８８８６２号で提案されている。この構造で
は親水性部分に貯蔵されているりん酸は電極触媒層５を
通ってマトリックス２に供給される。For example, by providing a hydrophilic portion on a part of the ribbed electrode base material 6 and using this hydrophilic portion as a reservoir for accumulating the electrolyte, the scattering of the electrolyte can be carried out without causing a reaction gas supply failure. JP-A-61-188862 proposes a fuel cell in which the electrolyte mass insufficient in the matrix is replenished and the volume change of the electrolyte in the matrix is absorbed. In this structure, phosphoric acid stored in the hydrophilic part is supplied to the matrix 2 through the electrode catalyst layer 5.

【０００７】図４は異なる従来の燃料電池の一例を示す
要部の斜視図であり、例えば燃料電極３の電極基材１
６，酸化剤電極４の電極基材１７を平板状の多孔質炭素
基材とし、電極基材１６，１７とセパレート板９との間
に溝付き多孔質炭素基材に予め電解質を含浸した溝付き
リザーバ板（第１の積層化素子とも呼ぶ）１１および１
２を設け、電極基材１６，１７との間に反応ガス通路８
を形成するするとともに、電極基材１６，１７を介して
溝付きリザーバ板１１，１２が貯留する電解質をマトリ
ックス２に供給するよう構成した燃料電池（単位セル）
１が、特開昭６２−２０２５５号で提案されている。こ
の場合、燃料電極３側の溝付きリザーバ板１１に予め電
解質を含浸しておき、はっ水処理しない燃料電極側の電
極基材１６を介してマトリックス２に電解質を補給する
とともに、反応ガス通路８内の反応ガスの流速を高める
ことによって電極基材１６のガス拡散性を保持し、かつ
酸化剤電極４側の電極基材１７は予めはっ水処理し、電
解質の補給を主に燃料電極３側の溝付きリザーバ板１１
からはっ水処理しない燃料電極側の電極基材１６を介し
て行うよう工夫されている。FIG. 4 is a perspective view of an essential part showing an example of a different conventional fuel cell, for example, the electrode base material 1 of the fuel electrode 3.
6, a groove in which the electrode base material 17 of the oxidizer electrode 4 is a flat plate-like porous carbon base material, and the porous carbon base material having a groove between the electrode base materials 16 and 17 and the separate plate 9 is impregnated with an electrolyte in advance. Reservoir plate (also called first stacking element) 11 and 1
2 is provided, and the reaction gas passage 8 is provided between the electrode base materials 16 and 17.
And a fuel cell (unit cell) configured to supply the electrolyte stored in the grooved reservoir plates 11 and 12 to the matrix 2 via the electrode base materials 16 and 17.
No. 1 is proposed in Japanese Patent Laid-Open No. 62-20255. In this case, the grooved reservoir plate 11 on the fuel electrode 3 side is preliminarily impregnated with an electrolyte, and the electrolyte is replenished to the matrix 2 via the electrode base material 16 on the fuel electrode side which is not water-repellent, and the reaction gas passage is provided. The gas diffusivity of the electrode base material 16 is maintained by increasing the flow rate of the reaction gas in the electrode 8, and the electrode base material 17 on the side of the oxidizer electrode 4 is preliminarily subjected to water repellent treatment to replenish electrolyte mainly for the fuel electrode. 3 side grooved reservoir plate 11
It is devised to carry out through the electrode base material 16 on the side of the fuel electrode which does not undergo water repellent treatment.

【０００８】また、図３におけるリブ付き電極基材６と
ガス不透過性のセパレート板との間に図示しない平板状
の多孔質炭素基材からなるリザーバ板を設け、かつリブ
付き電極基材６のはっ水処理に用いる処理液中のはっ水
性樹脂量を下げることにより、基材６に弱い親水性を残
し、基材６の内部で電解質の移動と反応ガスの拡散とを
両立させるよう工夫された燃料電池が特開平５−４１２
２３号で提案されている。In addition, a reservoir plate made of a flat plate-like porous carbon base material (not shown) is provided between the ribbed electrode base material 6 and the gas impermeable separate plate, and the ribbed electrode base material 6 is provided. By reducing the amount of the water-repellent resin in the treatment liquid used for the water-repellent treatment, the hydrophilicity is left in the base material 6 and the migration of the electrolyte and the diffusion of the reaction gas are made compatible inside the base material 6. A devised fuel cell is disclosed in JP-A-5-412.
Proposed in No. 23.

【０００９】さらに、リブ付きセパレータ方式の燃料電
池の場合、平板状のリザーバ板と電極基材の一部に親水
性部分を形成し、マトリックス中の電解質の体積膨張を
電極基材側の親水性部分を電解質移動経路として平板状
リザーバ板側の親水性部分に吸収するようにした燃料電
池が知られている（特公昭63-18303号）。一方、図４に
おける酸化剤電極４側の溝付きリザーバ板１２の空孔径
を酸化剤電極４側の部分的にはっ水処理した平板状の電
極基材１７の空孔径より小さくすることにより、平板状
の電極基材１７の電解質保持力を弱めて反応ガス透過性
を保持し、この状態で溝付きリザーバ板１２に十分な量
の電解質を貯蔵するようにした燃料電池が特開昭６３−
６４２６７号で提案されている。Further, in the case of the ribbed separator type fuel cell, a hydrophilic portion is formed on a flat reservoir plate and a part of the electrode base material so that the volume expansion of the electrolyte in the matrix becomes hydrophilic on the electrode base material side. A fuel cell is known in which a portion is used as an electrolyte transfer path to be absorbed by a hydrophilic portion on the side of a flat plate-like reservoir plate (Japanese Patent Publication No. 63-18303). On the other hand, by making the pore diameter of the grooved reservoir plate 12 on the oxidant electrode 4 side in FIG. 4 smaller than the pore diameter of the partially water-repellent plate-shaped electrode base material 17 on the oxidant electrode 4 side, A fuel cell in which the flat plate-like electrode base material 17 is weakened in electrolyte retention to retain reaction gas permeability and a sufficient amount of electrolyte is stored in the grooved reservoir plate 12 in this state is disclosed in Japanese Patent Laid-Open No. 63-
No. 64267 is proposed.

【００１０】[0010]

【発明が解決しようとする課題】親水性を有するリザー
バー板を設け、このリザーバー板から電解質としてのり
ん酸をマトリックスに補給する，あるいはりん酸の体積
変化を吸収する電解質移動経路として電極基材の一部に
親水性部分を設ける従来の燃料電池では、例えば電極基
材６または１１の親水性を残す部分にマスキングを施し
た状態で、残余の露出部分にはっ水性に富む物質（例え
ばＰＴＦＥ等）を含む処理液を塗布，含浸し、これを焼
成することにより親水性部分を有する基材を製作する方
法が用いられる。この方法では、マスキング作業が必要
になるめ電極基材の製造工数が増すことは勿論のこと、
基材が多孔質であるため処理液を吸収し易く，かつ処理
液に界面活性剤が含まれるためにマスキングした部分に
まで処理液が浸透してしまうために、どうしてもマスキ
ング面積が大きくなるとともに、処理液がしみ込む範囲
が一定になり難いため，そのばらつきを考慮して必要以
上の範囲を親水性とすることになり、これが原因ではっ
水性を有する部分の面積が縮小して反応ガスの透過性が
制限されるという問題があった。A reservoir plate having hydrophilicity is provided, and phosphoric acid as an electrolyte is replenished to the matrix from the reservoir plate, or the electrolyte substrate is used as an electrolyte transfer path for absorbing a volume change of phosphoric acid. In a conventional fuel cell in which a hydrophilic portion is partially provided, for example, in a state where the portion of the electrode base material 6 or 11 that remains hydrophilic is masked, the remaining exposed portion is a substance rich in water repellency (such as PTFE). Is applied and impregnated, and the substrate is baked to produce a substrate having a hydrophilic portion. In this method, masking work is required, which naturally increases the number of manufacturing steps of the electrode base material.
Since the base material is porous, it easily absorbs the treatment liquid, and since the treatment liquid contains a surfactant, the treatment liquid permeates even into the masked portion, which inevitably increases the masking area. The range in which the processing liquid penetrates is difficult to be constant, and therefore the range beyond what is necessary is made hydrophilic in consideration of the variation, and this causes the area of the part with water repellency to decrease and the reaction gas permeability to decrease. There was a problem that was limited.

【００１１】また、はっ水処理に用いる処理液のはっ水
性樹脂量を下げ、電極基材６または１１の全面に弱い親
水性を残すことにより、基材の内部で電解質の移動と反
応ガスの拡散とを両立させた場合には、燃料電池を長期
間運転する過程で電極基材が腐食性の強いりん酸によっ
て徐々に浸食され、フッ素樹脂によるはっ水性が低下し
て電極基材が濡れやすくなるため、ガス拡散性を長期間
安定して保持できる燃料電池を形成しにくいという問題
がある。ことに、燃料電極３側では電極基材６中の水素
の拡散性が優れており、電極基材へのりん酸の浸出量が
気孔容積の５０％程度までならば、発電性能に影響を及
ぼす程の反応ガス供給障害は認められない。これに対し
て、酸化剤電極４側では電極基材６中の水素の拡散性が
低く、電極基材へのりん酸の浸出量が気孔容積の３５を
越えると発電性能に影響を及ぼす程の反応ガス供給障害
が発生する。したがって、電極基材に弱い親水性を残し
た酸化剤電極側にリザーバを設けた場合には、運転中に
はっ水性が低下するに伴って酸化剤の供給障害を生じや
すくなることが懸念される。Further, the amount of the water-repellent resin of the treatment liquid used for the water-repellent treatment is reduced to leave a weak hydrophilic property on the entire surface of the electrode base material 6 or 11, so that the movement of the electrolyte and the reaction gas inside the base material can be prevented. In the process of operating the fuel cell for a long period of time, the electrode base material is gradually eroded by highly corrosive phosphoric acid, and the water repellency due to the fluororesin is reduced, and the electrode base material is Since it becomes easy to wet, there is a problem that it is difficult to form a fuel cell capable of stably maintaining gas diffusivity for a long period of time. In particular, on the fuel electrode 3 side, the diffusivity of hydrogen in the electrode base material 6 is excellent, and if the amount of phosphoric acid leached into the electrode base material is up to about 50% of the pore volume, the power generation performance is affected. No reaction gas supply failure was observed. On the other hand, the diffusibility of hydrogen in the electrode base material 6 is low on the oxidant electrode 4 side, and when the amount of phosphoric acid leached into the electrode base material exceeds 35, which is the pore volume, the power generation performance is affected. Reaction gas supply failure occurs. Therefore, when a reservoir is provided on the side of the oxidizer electrode where the electrode base material remains weakly hydrophilic, there is a concern that the supply of the oxidizer may be more likely to occur as the water repellency decreases during operation. It

【００１２】一方、酸化剤電極４側の溝付きリザーバ板
１２の細孔径を酸化剤電極４側の部分的にはっ水処理し
た平板状の電極基材１７の細孔径より小さくすることに
より、平板状の電極基材１７の反応ガス透過性を保持し
た状態で溝付きリザーバ板１２に十分な量の電解質を貯
蔵する従来技術では、酸化剤電極４側のはっ水処理につ
いて前記と同様な問題が存在すると同時に、水素に比べ
て透過性の低い酸化剤としての酸素の透過が電極基材の
親水性部分の存在によって阻害され、酸化剤の拡散不良
を生じやすくなるという問題が発生する。さらに、燃料
電極３側の電極基材１６を親水性，酸化剤電極４側の電
極基材１７をはっ水性とし、電解質の補給を主に燃料電
極３側の溝付きリザーバ板１１からはっ水処理しない燃
料電極側の電極基材１６を介して行うようにした従来技
術では、電極基材１７をはっ水性とすることによって酸
化剤の拡散不良を生じにくくできるものの、電極基材１
７のはっ水性によって電解質の移動が阻害され、折角設
けた酸化剤電極４側の溝付きリザーバ板１２が電解質の
呼吸作用に有効に作用しないという問題がある。On the other hand, by making the pore size of the grooved reservoir plate 12 on the oxidant electrode 4 side smaller than that of the partially water-repellent plate-like electrode base material 17 on the oxidant electrode 4 side, In the conventional technique in which a sufficient amount of electrolyte is stored in the grooved reservoir plate 12 while the reaction gas permeability of the flat plate-shaped electrode base material 17 is maintained, the water repellent treatment on the oxidant electrode 4 side is the same as that described above. At the same time that there is a problem, there is a problem in that the permeation of oxygen as an oxidant having a lower permeability than hydrogen is hindered by the presence of the hydrophilic portion of the electrode base material, so that a poor diffusion of the oxidant easily occurs. Further, the electrode base material 16 on the fuel electrode 3 side is made hydrophilic, and the electrode base material 17 on the oxidizer electrode 4 side is made water repellent, so that the electrolyte is supplied mainly from the grooved reservoir plate 11 on the fuel electrode 3 side. In the conventional technique in which the water treatment is performed via the electrode base material 16 on the fuel electrode side, although the electrode base material 17 is made water repellent, the diffusion failure of the oxidizer can be less likely to occur.
There is a problem that the water repellency of 7 hinders the movement of the electrolyte, and the grooved reservoir plate 12 on the side of the oxidant electrode 4 provided at a corner does not effectively act on the breathing action of the electrolyte.

【００１３】この発明の目的は、酸化剤の拡散不良を生
ずることなく、酸化剤電極側リザーバとマトリックスと
の間のりん酸の移動を円滑化できるりん酸型燃料電池を
提供することにある。An object of the present invention is to provide a phosphoric acid fuel cell capable of facilitating the transfer of phosphoric acid between the oxidant electrode side reservoir and the matrix without causing oxidant diffusion failure.

【００１４】[0014]

【課題を解決するための手段】上述の課題を解決するた
めに、この発明のりん酸型燃料電池は、多孔質の非導電
性基材中にりん酸を保持したマトリックスと、このマト
リックスを挟んでその両側に積層された燃料電極および
酸化剤電極と、この燃料電極および酸化剤電極を挟んで
その両側にリブ部分が密接して反応ガス通路を形成する
親水性を有するリブ付き多孔質炭素基材からなるリザー
バ板とを備えた単位セルを、ガス不透過性のセパレート
板を介在させて複数層積層したりん酸型燃料電池におい
て、前記一対の電極の少なくとも酸化剤電極が予めはっ
水処理した平板状の多孔質炭素板からなる電極基材と、
その一方の面に支持された電極触媒層とからなり、この
酸化剤電極の周縁部の少なくとも一部に前記マトリック
スとリザーバ板とに挟持された多孔質部材からなるりん
酸移動経路部を備える。In order to solve the above-mentioned problems, the phosphoric acid fuel cell of the present invention has a matrix in which phosphoric acid is held in a porous non-conductive substrate, and the matrix is sandwiched between the matrix. And a porous carbon group with ribs having hydrophilicity in which the fuel electrode and the oxidant electrode are laminated on both sides thereof, and the rib portions are in close contact with each other across the fuel electrode and the oxidant electrode to form a reaction gas passage. In a phosphoric acid fuel cell in which a plurality of unit cells having a reservoir plate made of a material are laminated with a gas-impermeable separate plate interposed, at least the oxidant electrode of the pair of electrodes is preliminarily subjected to water repellent treatment. An electrode substrate made of a flat plate-like porous carbon plate,
An electrocatalyst layer supported on one surface of the oxidant electrode is provided, and at least a part of the peripheral edge of the oxidizer electrode is provided with a phosphoric acid transfer path portion made of a porous member sandwiched between the matrix and the reservoir plate.

【００１５】ここで、りん酸移動経路部を、炭化けい素
粉末を主原料とする親水性の多孔質非導電性材、あるい
は親水性を有する多孔質炭素板材とすると良い。また、
りん酸移動経路部の酸化剤電極側電極基材の厚みに相応
する部分を、酸化剤電極側電極基材の延長部分とし、こ
の延長部分を予め親水性処理すると良く、さらに親水性
処理部は、あらかじめはっ水処理した平板状の多孔質炭
素板からなる電極基材の延長部分にレーザー光線を照射
し、はっ水性物質を除去すると良い。Here, the phosphoric acid transfer path portion is preferably a hydrophilic porous non-conductive material whose main raw material is silicon carbide powder, or a hydrophilic porous carbon plate material. Also,
The portion corresponding to the thickness of the oxidant electrode side electrode base material of the phosphoric acid migration path is an extension part of the oxidizer electrode side electrode base material, and this extension part may be previously subjected to hydrophilic treatment. It is advisable to irradiate a laser beam on an extended portion of an electrode base material made of a flat plate-like porous carbon plate that has been previously treated with water repellency to remove the water repellent substance.

【００１６】一方、マトリックスを挟んでりん酸移動経
路部に対向する燃料電極部分および燃料電極側リザーバ
部分には、ガス不透過性のシール材を配置すると良い。On the other hand, a gas-impermeable sealing material may be arranged in the fuel electrode portion and the fuel electrode side reservoir portion which face the phosphoric acid migration path portion with the matrix interposed therebetween.

【００１７】[0017]

【作用】この発明のりん酸型燃料電池においては、単位
セルの周縁部に設けた多孔質部材からなるりん酸移動経
路部を通してマトリックスとリザーバ板と間でりん酸の
移動が行われることになり、電解質の飛散によりマトリ
ックス中で不足する電解質をリザーバ板から補給し、ま
たマトリックス中の電解質の体積変化をリザーバ板が吸
収するりん酸の呼吸作用を円滑化する。また、酸化剤電
極の予めはっ水処理した平板状の多孔質炭素板からなる
電極基材は、りん酸の浸出を阻止して酸化剤の透過性を
保持し、酸化剤の拡散不良を防止する。従って、りん酸
の移動経路と酸化剤の拡散経路は分離され、りん酸の呼
吸機能と酸化剤の供給機能とを確実に両立させることが
できる。In the phosphoric acid fuel cell of the present invention, the phosphoric acid moves between the matrix and the reservoir plate through the phosphoric acid moving path portion formed of the porous member provided at the peripheral portion of the unit cell. , Replenish the electrolyte deficient in the matrix due to the scattering of the electrolyte from the reservoir plate, and smooth the respiratory action of phosphoric acid absorbed by the reservoir plate due to the volume change of the electrolyte in the matrix. In addition, the electrode base material consisting of a flat porous carbon plate that has been pre-hydrophobized for the oxidizer electrode prevents the leaching of phosphoric acid and retains the permeability of the oxidizer, thus preventing the diffusion failure of the oxidizer. To do. Therefore, the migration path of phosphoric acid and the diffusion path of oxidant are separated, and the respiratory function of phosphoric acid and the supply function of oxidant can be reliably achieved at the same time.

【００１８】ここで、りん酸移動経路部として、炭化け
い素粉末を主原料とする親水性の多孔質非導電性材、あ
るいは親水性を有する多孔質炭素板材を用いることによ
り、りん酸に対する多孔質部材の濡れ性を保持できるの
で、液切れを生ずることなくりん酸の移動を円滑に行う
ことができる。また、りん酸移動経路部の酸化剤電極側
電極基材の厚みに相応する部分を、酸化剤電極側電極基
材の延長部分とし、この延長部分を予め親水性処理すれ
ば、この延長部分をリザーバーの一部に利用して溜め込
むりん酸保持量を増大することができる。さらに、親水
性処理部は、予めはっ水処理した平板状の多孔質炭素板
からなる電極基材の延長部分にレーザー光線を照射し、
はっ水性物質を除去することにより、容易に親水性を得
ることができる。Here, by using a hydrophilic porous non-conductive material containing silicon carbide powder as a main raw material or a porous carbon plate material having hydrophilicity as the phosphoric acid transfer path portion, it is possible to obtain a porous structure for phosphoric acid. Since the wettability of the quality member can be maintained, the phosphoric acid can be smoothly moved without causing the liquid to run out. In addition, a portion of the phosphoric acid migration path portion corresponding to the thickness of the electrode base material on the oxidant electrode side is used as an extended portion of the electrode base material on the oxidant electrode side. The amount of phosphoric acid retained in the reservoir can be increased by utilizing it in a part of the reservoir. Furthermore, the hydrophilic treatment portion irradiates a laser beam on an extended portion of the electrode base material made of a flat plate-like porous carbon plate that has been previously subjected to water repellency,
Hydrophilicity can be easily obtained by removing the water-repellent substance.

【００１９】一方、マトリックスを挟んでりん酸移動経
路部に対向する燃料電極部分および燃料電極側リザーバ
部分にガス不透過性のシール材を配置するようにすれ
ば、りん酸移動経路部への反応ガスの供給が阻止され、
電極有効面積の外側の発電に寄与してシール部にりん酸
移動経路部を配置することが可能になる。On the other hand, if a gas-impermeable sealing material is arranged at the fuel electrode portion and the fuel electrode side reservoir portion facing the phosphoric acid transfer path portion with the matrix sandwiched therebetween, the reaction to the phosphoric acid transfer path portion will occur. Gas supply is cut off,
It is possible to dispose the phosphoric acid transfer path portion in the seal portion by contributing to power generation outside the effective electrode area.

【００２０】[0020]

【実施例】以下この発明を実施例に基づいて説明する。
図１はこの発明の実施例になるりん酸型燃料電池の要部
を示す斜視図であり、従来例と同じ参照符号を付けた部
材は従来例のそれと同じ機能をもつので、その説明を省
略する。図において、単位セル２０は多孔質の非導電性
基材中にりん酸を保持したマトリックス２と、このマト
リックスを挟んでその両側に積層された燃料電極３およ
び酸化剤電極４と、この燃料電極および酸化剤電極を挟
んでその両側にリブ部分７が密接して反応ガス通路８を
形成する親水性を有するリブ付き多孔質炭素基材（例え
ば気孔率５５〜７０％程度）からなるリザーバ板２１
（燃料電極側），２２（酸化剤電極側）との積層体とし
て構成される。また、燃料電極３および酸化剤電極４は
それぞれ白金などの電極触媒を担持した電極触媒層５
と、ガス透過性を有する多孔質炭素板からなる平板状の
電極基材２６（燃料電極側）または２７（酸化剤電極
側）との積層体からなり、少なくとも酸化剤電極側の電
極基材２７には酸化剤の拡散を長期に渡って維持するた
めに全面にはっ水処理が施される。はっ水処理の条件と
しては、はっ水性物質であるＰＴＦＥ懸濁液（商品名：
テフロン３０Ｊディスパージョン）と純水を重量比１：
４で混合した処理液に基材を浸漬し、室温で１時間乾燥
した後、３５０°Ｃの乾燥炉内で３０分焼成することに
より、長期安定性に優れた強固なはっ水性が得られる。EXAMPLES The present invention will be described below based on examples.
FIG. 1 is a perspective view showing a main part of a phosphoric acid fuel cell according to an embodiment of the present invention. Since members having the same reference numerals as those of the conventional example have the same functions as those of the conventional example, description thereof will be omitted. To do. In the figure, a unit cell 20 is composed of a matrix 2 in which phosphoric acid is held in a porous non-conductive substrate, a fuel electrode 3 and an oxidizer electrode 4 which are laminated on both sides of the matrix, and the fuel electrode. And a reservoir plate 21 made of a porous ribbed carbon base material (for example, having a porosity of about 55 to 70%) having hydrophilicity in which the rib portions 7 are in close contact with each other across the oxidizer electrode to form the reaction gas passage 8.
(Fuel electrode side), 22 (Oxidizer electrode side). Further, the fuel electrode 3 and the oxidant electrode 4 are each an electrode catalyst layer 5 carrying an electrode catalyst such as platinum.
And a flat plate-shaped electrode base material 26 (fuel electrode side) or 27 (oxidizer electrode side) made of a porous carbon plate having gas permeability, and at least an electrode base material 27 on the oxidizer electrode side. In order to maintain the diffusion of the oxidant for a long period of time, the entire surface is subjected to water repellency treatment. The conditions for water repellent treatment include PTFE suspension, which is a water repellent substance (trade name:
Teflon 30J dispersion) and pure water in a weight ratio of 1:
By immersing the substrate in the treatment liquid mixed in 4, drying at room temperature for 1 hour, and baking it in a drying oven at 350 ° C for 30 minutes, a strong water repellency excellent in long-term stability can be obtained. .

【００２１】また、酸化剤電極４はその周縁部の少なく
とも一部（図では一定の幅Ｗ）が切り欠かれ、この切り
欠き部分にマトリックス２とリザーバ板２２とに挟持さ
れた多孔質部材からなるりん酸移動経路部２３が介装さ
れる。ここで、りん酸移動経路部２３には、炭化けい素
粉末を主原料とする親水性の多孔質非導電性材、あるい
は親水性を有する多孔質炭素板材にりん酸を含浸したも
のが用いられ、りん酸に対する多孔質部材の濡れ性を保
持することにより、りん酸移動経路部２３内で液切れを
生ずることなく、マトリックス２とリザーバ板２２との
間でりん酸の移動が行われる。従って、リザーバ板２２
に一定量のりん酸を予め含浸しておくことにより、りん
酸の飛散によりマトリックス２中で不足するりん酸をリ
ザーバ板２２から補給し、またマトリックス２中のりん
酸の体積変化をリザーバ板２２が吸収するりん酸の呼吸
作用をりん酸移動経路部２３を介して円滑に行うことが
できる。Further, at least a part (a constant width W in the figure) of the peripheral portion of the oxidizer electrode 4 is cut out, and the cutout portion is formed of a porous member sandwiched between the matrix 2 and the reservoir plate 22. The phosphoric acid transfer path part 23 is interposed. Here, for the phosphoric acid transfer path portion 23, a hydrophilic porous non-conductive material whose main raw material is silicon carbide powder, or a hydrophilic porous carbon plate material impregnated with phosphoric acid is used. By maintaining the wettability of the porous member with respect to phosphoric acid, the phosphoric acid can be transferred between the matrix 2 and the reservoir plate 22 without running out of liquid in the phosphoric acid transfer path portion 23. Therefore, the reservoir plate 22
By impregnating a certain amount of phosphoric acid in advance, the phosphoric acid deficient in the matrix 2 due to the scattering of phosphoric acid is replenished from the reservoir plate 22, and the volume change of the phosphoric acid in the matrix 2 is corrected by the reservoir plate 22. The breathing action of the phosphoric acid absorbed by the can be smoothly performed through the phosphoric acid transfer path portion 23.

【００２２】また、燃料電極３および燃料電極側のリザ
ーバ板２１も、マトリックス２を挟んでりん酸移動経路
部２３に対向する部分が切り欠かれ、この部分にガス不
透過性のシール材２９が介装される。このように構成す
ることにより、りん酸移動経路部２３への燃料ガスの供
給が阻止され、かつ電極触媒層５の外側に置かれること
になり、りん酸移動経路部２３は発電に寄与しない。し
たがって、従来発電に寄与しない単位セル周縁のシール
部を利用してりん酸移動経路部２３を形成することが可
能であり、単位セル２０の発電性能に影響を及ぼすこと
なくりん酸移動経路部を形成できる利点が得られる。Further, the fuel electrode 3 and the reservoir plate 21 on the fuel electrode side are also cut out at a portion facing the phosphoric acid transfer path portion 23 with the matrix 2 in between, and a gas impermeable sealing material 29 is provided at this portion. Intervened. With this configuration, the supply of fuel gas to the phosphoric acid transfer path portion 23 is blocked, and the fuel gas is placed outside the electrode catalyst layer 5, so that the phosphoric acid transfer path portion 23 does not contribute to power generation. Therefore, it is possible to form the phosphoric acid transfer path part 23 by utilizing the seal part at the peripheral edge of the unit cell that does not contribute to power generation, and the phosphoric acid transfer path part can be formed without affecting the power generation performance of the unit cell 20. The advantage is that it can be formed.

【００２３】一方、酸化剤電極４はりん酸移動経路部２
３から切り離され、かつその電極基材２７が全面はっ水
処理されてりん酸の浸出を阻止し、酸化剤の拡散に必要
な気孔率を安定して保持するので、電極基材に部分的に
はっ水性を持たせた従来技術，あるいは全面に弱いはっ
水性を持たせた従来技術で問題になった酸化剤の拡散不
良は排除され、りん酸の移動経路と酸化剤の拡散経路が
分離され、りん酸の呼吸機能と酸化剤の供給機能とをほ
ぼ完全に両立させたりん酸型燃料電池が得られる。ま
た、燃料電極３側にも図示しないりん酸移動経路部を設
け、リザーバ板２１にも予め一定量のりん酸を含浸して
おくことにより、リザーバ板が保持するりん酸量を凡そ
２倍近くに増量できるので、りん酸の不足による発電性
能の低下を長時間に渡り抑制することができる。さら
に、酸化剤電極４側に生成する発電生成水の水蒸気とと
もに飛散するりん酸は、電極基材２７を透過してリザー
バ板２２の凹溝からなる反応ガス通路８内で凝縮し、リ
ザーバ板２２内に吸収されて回収できるためにりん酸の
消失量を低減することが可能であり、より一層外部から
のりん酸の補給間隔を延長することが可能であり、りん
酸型燃料電池の保守管理を省力化し、長期連続運転を可
能にする利点が得られる。On the other hand, the oxidant electrode 4 is the phosphoric acid migration path 2
3 is separated from the electrode base material 27, and the entire surface of the electrode base material 27 is subjected to water repellency treatment to prevent the leaching of phosphoric acid and to stably maintain the porosity necessary for the diffusion of the oxidizer. The poor diffusion of the oxidant, which has been a problem with the conventional technology with water repellency or the conventional technology with weak water repellency on the entire surface, is eliminated, and the migration route of phosphoric acid and the diffusion route of oxidant are eliminated. A phosphoric acid fuel cell which is separated and has a breathing function of phosphoric acid and a supply function of an oxidant almost completely compatible with each other can be obtained. Further, by providing a phosphoric acid transfer path portion (not shown) also on the fuel electrode 3 side and preliminarily impregnating the reservoir plate 21 with a fixed amount of phosphoric acid, the amount of phosphoric acid held by the reservoir plate is nearly doubled. Therefore, it is possible to suppress the deterioration of the power generation performance due to the shortage of phosphoric acid for a long time. Further, the phosphoric acid that is scattered along with the steam of the power generation water generated on the oxidant electrode 4 side passes through the electrode base material 27 and is condensed in the reaction gas passage 8 formed of the concave groove of the reservoir plate 22, and the reservoir plate 22. Since it is absorbed inside and can be recovered, it is possible to reduce the amount of phosphoric acid lost, and it is possible to further extend the replenishment interval of phosphoric acid from the outside, and to maintain phosphoric acid fuel cells It is possible to obtain the advantage of saving labor and enabling long-term continuous operation.

【００２４】ところで、燃料電極３側では電極基材２６
中の水素の拡散性が優れており、電極基材２６へのりん
酸の浸出量が気孔容積の５０％程度までならば、発電性
能に影響を及ぼす程の反応ガス供給障害は認められな
い。したがって、例えば電極基材２６の細孔径を５０〜
１００μｍとリザーバ板２２の細孔径２０μｍより大き
くすることにより、電極基材２６へのりん酸の浸出量を
気孔容積の４０％以下に維持することが可能であり、し
たがって、燃料電極３側には親水性を有する電極基材２
７を用いても良く、りん酸の呼吸機能と酸化剤の供給機
能とを両立させることも可能である。By the way, on the fuel electrode 3 side, the electrode base material 26
When the diffusibility of hydrogen in the inside is excellent and the amount of phosphoric acid leached into the electrode base material 26 is up to about 50% of the pore volume, no reaction gas supply obstacle that affects power generation performance is recognized. Therefore, for example, the pore diameter of the electrode base material 26 is 50 to
By making the pore size of 100 μm and the pore size of the reservoir plate 22 larger than 20 μm, the amount of phosphoric acid leaching into the electrode base material 26 can be maintained at 40% or less of the pore volume. Electrode substrate 2 having hydrophilicity
7 may be used, and it is also possible to make the breathing function of phosphoric acid and the supply function of the oxidant compatible with each other.

【００２５】図２はこの発明の異なる実施例になるりん
酸型燃料電池の要部を示す側面図であり、単位セル３０
は、そのりん酸移動経路部３１の酸化剤電極側電極基材
２７の厚みに相応する部分がはっ水性の酸化剤電極側電
極基材２７の延長部分を親水性処理した部材３２からな
り、残る酸化剤電極側電極触媒層５の厚みに相応する部
分を前述の実施例と同様に、炭化けい素粉末を主原料と
する親水性の多孔質非導電性材、あるいは親水性を有す
る多孔質炭素板材（例えば、気孔率５０〜８０％，平均
細孔径１０〜３０μｍのカーボンペーパー）３３で構成
された点が前述の実施例と異なっており、この延長部分
３２をリザーバーの一部に利用して溜め込むりん酸保持
量を増大できる利点が得られる。なお、電極基材２７の
延長部分３２の親水性処理は、予めはっ水処理した電極
基材２７の延長部分３２にレーザー光線（例えばＹＡＧ
レーザー）を照射し、はっ水性物質を除去することによ
り、容易に親水性を得ることができる。FIG. 2 is a side view showing a main part of a phosphoric acid fuel cell according to a different embodiment of the present invention.
Is a member 32 in which a portion of the phosphoric acid migration path portion 31 corresponding to the thickness of the oxidant electrode side electrode base material 27 is made hydrophilic by processing an extended portion of the water repellent oxidant electrode side electrode base material 27. A portion corresponding to the thickness of the remaining oxidant electrode side electrode catalyst layer 5 is a hydrophilic porous non-conductive material or a hydrophilic porous material whose main raw material is silicon carbide powder, as in the above-mentioned embodiment. It differs from the above-mentioned embodiment in that it is composed of a carbon plate material (for example, carbon paper having a porosity of 50 to 80% and an average pore diameter of 10 to 30 μm) 33. This extended portion 32 is used as a part of a reservoir. The advantage is that the amount of phosphoric acid retained can be increased. The hydrophilic treatment of the extension portion 32 of the electrode base material 27 is performed by applying a laser beam (for example, YAG) to the extension portion 32 of the electrode base material 27 which has been previously water-repellent treated.
A hydrophilic property can be easily obtained by irradiating a laser) to remove the water-repellent substance.

【００２６】[0026]

【発明の効果】この発明のりん酸型燃料電池は前述のよ
うに、単位セルの一対の電極の電極有効面積の外側にり
ん酸移動経路部を設け、マトリックスとリザーバ板との
間のりん酸の移動をりん酸移動経路部を介して行うとと
もに、はっ水処理した電極基材を介して反応ガスの供給
を行うよう構成した、その結果、りん酸の移動経路と酸
化剤の拡散経路とがほぼ完全に分離されて従来問題にな
った相互の悪影響が排除され、りん酸呼吸機能と酸化剤
の供給機能とに優れ，長期運転性能が安定したりん酸型
燃料電池を提供することができる。As described above, the phosphoric acid fuel cell of the present invention is provided with a phosphoric acid migration path portion outside the electrode effective area of the pair of electrodes of the unit cell, and the phosphoric acid between the matrix and the reservoir plate is provided. The reaction gas is supplied through the phosphoric acid transfer path portion and the reaction gas is supplied through the water repellent electrode base material. As a result, the phosphoric acid transfer path and the oxidant diffusion path are It is possible to provide a phosphoric acid fuel cell in which the mutual adverse effects that have become problems due to the prior art are eliminated almost completely, the phosphoric acid breathing function and the oxidizing agent supply function are excellent, and the long-term operation performance is stable. .

【００２７】また、燃料電極側のリザーバ板はもとよ
り、ガス拡散性の低い酸化剤電極側のリザーバ板もりん
酸移動経路部によりガス拡散性能を阻害することなくり
ん酸の貯蔵に有効利用できるので、従来の単位セルに比
べて凡そ２倍の量のりん酸を保持することが可能とな
り、りん酸の不足による特性低下を長期間に渡って抑制
できる利点が得られる。Further, not only the reservoir plate on the fuel electrode side but also the reservoir plate on the oxidant electrode side having a low gas diffusivity can be effectively used for storage of phosphoric acid without impeding the gas diffusion performance by the phosphoric acid migration path portion. As compared with the conventional unit cell, it is possible to retain approximately twice as much phosphoric acid, and there is an advantage that deterioration of characteristics due to lack of phosphoric acid can be suppressed for a long period of time.

【００２８】さらに、酸化剤電極の電極反応に伴って水
蒸気が発生するために飛散するりん酸は、機能分離によ
って強固にはっ水処理された電極基材を透過し、反応ガ
ス通路で再凝縮してリザーバ板に回収されるとともに、
りん酸移動経路部を介してマトリックスに還流して再利
用できるので、外部からのりん酸の補給間隔を延長し、
りん酸型燃料電池の保守管理を省力化できるとともに、
長期連続運転を可能にする利点が得られる。Further, the phosphoric acid which is scattered due to the generation of water vapor accompanying the electrode reaction of the oxidant electrode passes through the electrode base material which is strongly water-repellent treated by the functional separation, and is recondensed in the reaction gas passage. And then collected in the reservoir plate,
Since it can be reused by refluxing to the matrix through the phosphate transfer route, the interval of external phosphate supply can be extended,
The maintenance management of the phosphoric acid fuel cell can be reduced, and
The advantage that long-term continuous operation is possible is obtained.

【００２９】なお、りん酸移動経路部は、電池の構成状
不可欠なシール部として当初より反応に寄与しない部分
として計画されたスペースを利用して形成できるので、
電極有効面積の縮小を伴うことなくりん酸の呼吸機能が
得られることになり、予めはっ水処理された電極基材の
反応ガス供給性能の向上効果と併せて発電性能の向上が
期待される。Since the phosphoric acid transfer path portion can be formed by utilizing the space originally planned as a portion which does not contribute to the reaction as a seal portion which is indispensable for the constitution of the battery,
The phosphoric acid breathing function can be obtained without reducing the effective electrode area, and it is expected that the power generation performance will be improved together with the effect of improving the reaction gas supply performance of the electrode base material that has been previously water-repellent treated. .

【図面の簡単な説明】[Brief description of drawings]

【図１】この発明の実施例になるりん酸型燃料電池の要
部を示す斜視図FIG. 1 is a perspective view showing a main part of a phosphoric acid fuel cell according to an embodiment of the present invention.

【図２】この発明の異なる実施例になるりん酸型燃料電
池の要部を示す側面図FIG. 2 is a side view showing a main part of a phosphoric acid fuel cell according to another embodiment of the present invention.

【図３】リブ付電極方式のりん酸型燃料電池の従来の単
位セルを展開して示す斜視図FIG. 3 is a perspective view showing a developed unit cell of a phosphoric acid fuel cell of a ribbed electrode type in a conventional manner.

【図４】異なる従来の燃料電池の一例を示す要部の斜視
図FIG. 4 is a perspective view of a main part showing an example of a different conventional fuel cell.

【符号の説明】[Explanation of symbols]

１ 単位セル ２ 電解質層（マトリックス） ３ 燃料電極 ４ 酸化剤電極（空気電極） ５ 電極触媒層 ６ リブ付き電極基材 ７ リブ ８ 反応ガス供給溝（反応ガス通路） ９ セパレ−ト板 １０ 単位セル １１ 溝付きリザーバ板（燃料電極側） １２ 溝付きリザーバ板（酸化剤電極側） １６ 電極基材（燃料電極側） １７ 電極基材（酸化剤電極側） ２０ 単位セル ２１ リザーバ板（燃料電極側） ２２ リザーバ板（酸化剤電極側） ２３ りん酸移動経路部 ２６ 電極基材（燃料電極側） ２７ 電極基材（酸化剤電極側，はっ水性） ２９ シール材 ３０ 単位セル ３１ りん酸移動経路部 ３２ 電極基材の延長部分（親水性） ３３ 多孔質部材 1 unit cell 2 electrolyte layer (matrix) 3 fuel electrode 4 oxidizer electrode (air electrode) 5 electrode catalyst layer 6 electrode base material with ribs 7 ribs 8 reaction gas supply groove (reaction gas passage) 9 separate plate 10 unit cell 11 Reservoir plate with groove (fuel electrode side) 12 Reservoir plate with groove (oxidant electrode side) 16 Electrode base material (fuel electrode side) 17 Electrode base material (oxidizer electrode side) 20 Unit cell 21 Reservoir plate (fuel electrode side) ) 22 Reservoir plate (oxidant electrode side) 23 Phosphoric acid transfer path part 26 Electrode base material (fuel electrode side) 27 Electrode base material (oxidizer electrode side, water repellency) 29 Sealing material 30 Unit cell 31 Phosphoric acid transfer path Part 32 Extension part of electrode base material (hydrophilic) 33 Porous member

Claims (6)

【特許請求の範囲】[Claims] 【請求項１】多孔質の非導電性基材中にりん酸を保持し
たマトリックスと、このマトリックスを挟んでその両側
に積層された燃料電極および酸化剤電極と、この燃料電
極および酸化剤電極を挟んでその両側にリブ部分が密接
して反応ガス通路を形成する親水性を有するリブ付き多
孔質炭素基材からなるリザーバ板とを備えた単位セル
を、ガス不透過性のセパレート板を介在させて複数層積
層したりん酸型燃料電池において、前記一対の電極の少
なくとも酸化剤電極が予めはっ水処理した平板状の多孔
質炭素板からなる電極基材と、その一方の面に支持され
た電極触媒層とからなり、この酸化剤電極の周縁部の少
なくとも一部に前記マトリックスとリザーバ板とに挟持
された多孔質部材からなるりん酸移動経路部を備えたこ
とを特徴とするりん酸型燃料電池。1. A matrix in which phosphoric acid is held in a porous non-conductive substrate, a fuel electrode and an oxidant electrode laminated on both sides of the matrix, and the fuel electrode and the oxidant electrode. A unit cell provided with a reservoir plate made of a hydrophilic ribbed porous carbon base material, in which the rib portions are in close contact with each other to form a reaction gas passage, and a gas impermeable separate plate is interposed. In a phosphoric acid fuel cell having a plurality of laminated layers, at least the oxidant electrode of the pair of electrodes is supported on one surface thereof by an electrode base material made of a flat plate-like porous carbon plate that has been previously water-repellent treated. And a phosphoric acid transfer path portion composed of a porous member sandwiched between the matrix and the reservoir plate at least at a part of a peripheral portion of the oxidizer electrode. Type fuel cell. 【請求項２】りん酸移動経路部が炭化けい素粉末を主原
料とする親水性の多孔質非導電性材からなることを特徴
とする請求項１記載のりん酸型燃料電池。2. The phosphoric acid fuel cell according to claim 1, wherein the phosphoric acid transfer path portion is made of a hydrophilic porous non-conductive material whose main raw material is silicon carbide powder. 【請求項３】りん酸移動経路部が親水性を有する多孔質
炭素板材からなることを特徴とする請求項１記載のりん
酸型燃料電池。3. The phosphoric acid fuel cell according to claim 1, wherein the phosphoric acid transfer path portion is made of a hydrophilic porous carbon plate material. 【請求項４】りん酸移動経路部の酸化剤電極側電極基材
の厚みに相応する部分が酸化剤電極側電極基材の延長部
分からなり、この延長部分が予め親水性処理されてなる
ことを特徴とする請求項１，請求項２，請求項３のいず
れかに記載のりん酸型燃料電池。4. A portion of the phosphoric acid migration path portion corresponding to the thickness of the electrode base material on the oxidant electrode side is an extended portion of the electrode base material on the oxidant electrode side, and the extended portion is previously subjected to hydrophilic treatment. The phosphoric acid fuel cell according to any one of claims 1, 2 and 3, characterized in that 【請求項５】親水性処理部が予めはっ水処理した平板状
の多孔質炭素板からなる電極基材孔の延長部分にレーザ
ー光線を照射し、はっ水性物質を除去してなることを特
徴とする請求項４記載のりん酸型燃料電池。5. A hydrophilic treatment portion is formed by irradiating a laser beam to an extended portion of an electrode base material hole made of a flat plate-like porous carbon plate which has been previously subjected to water repellency to remove the water repellent substance. The phosphoric acid fuel cell according to claim 4. 【請求項６】マトリックスを挟んでりん酸移動経路部に
対向する燃料電極部分および燃料電極側リザーバ部分
に、ガス不透過性のシール材を配したことを特徴とする
請求項１記載のりん酸型燃料電池。6. The phosphoric acid according to claim 1, wherein a gas-impermeable sealing material is arranged in the fuel electrode portion and the fuel electrode side reservoir portion which face the phosphoric acid migration path portion with the matrix interposed therebetween. Type fuel cell.