JPH0547398A - Electrolyte impregnating method for fuel cell electrode catalyst layer - Google Patents

Abstract

PURPOSE:To reduce the dispersion of the impregnation quantity and the work man-hours and facilitate storage by assembling a stack via separators and liquid-cooled cooling plates, then heating the cooling plates with hot water, and transferring and impregnating an electrolyte to electrode catalyst layers. CONSTITUTION:A reservoir plate 7 impregnated with an electrolyte 9 in advance and a separator 5 are arranged on both faces of a unit cell 1, a liquid-cooled cooling plate 12 is arranged for multiple unit cells 1, and they are laminated and applied with the preset face pressure by a fastening device to form a stack 11. Cooling water is fed to the cooling plates 12 during the cell operation to discharge the heat caused by power generation. For the impregnation of the electrolyte 9, hot water at about 160 deg.C is fed to a cooling pipe from the outside, the viscosity of phosphoric acid is made a value suitable for impregnation to increase fluidity, and the electrolyte 9 is uniformly transferred and impregnated to electrode catalyst layers 3A, 4A closely stuck to a matrix 2. The impregnation can be concurrently performed on multiple unit cells 1, and the work man- hours can be sharply reduced.

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、例えば粘度および吸
湿性の高いりん酸を電解液とする燃料電池における電極
触媒層への電解液含浸方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for impregnating an electrode catalyst layer with an electrolyte solution in a fuel cell using, for example, phosphoric acid having high viscosity and hygroscopicity as an electrolyte solution.

【０００２】[0002]

【従来の技術】図３はりん酸形燃料電池の単電池構造を
示す展開図であり、リブ付電極方式の単電池を例に示し
たものである。図において、単電池１は電解液としての
りん酸をあらかじめ含浸したマトリックス２と、その一
方の面に電極触媒層３Ａが密着するよう多孔質支持基材
３Ｂに支持された燃料電極３と、マトリックス２の他方
の面に電極触媒層４Ａが密着するよう多孔質支持基材４
Ｂに支持された酸化剤電極４との積層体として形成さ
れ、あらかじめ撥水（はっ水）処理された多孔質支持基
材３Ｂ，４Ｂのうち燃料電極３側の多孔質支持基材３Ｂ
にははっ水処理しない親水性通路３Ｃが形成される。こ
のように構成された単電池１には、多孔質支持基材３Ｂ
側にりん酸を含ませたカ−ボンペ−パ−等で形成された
リザ−バプレ−ト６を配し、多孔質支持基材４Ｂ側には
ガス不透過性のセパレ−タ５を配し、上記積層体を複数
層毎に図示しない液冷式の冷却板を挟んで積層すること
により積層型燃料電池（スタック）が形成される。2. Description of the Related Art FIG. 3 is a development view showing a unit cell structure of a phosphoric acid fuel cell, and shows an example of a ribbed electrode type cell. In the figure, a unit cell 1 comprises a matrix 2 pre-impregnated with phosphoric acid as an electrolytic solution, a fuel electrode 3 supported on a porous support substrate 3B so that an electrode catalyst layer 3A is adhered to one surface thereof, and a matrix. The porous support substrate 4 so that the electrode catalyst layer 4A adheres to the other surface of
The porous support base material 3B on the fuel electrode 3 side among the porous support base materials 3B, 4B which are formed as a laminate with the oxidant electrode 4 supported by B and have been previously subjected to water repellent (water repellent) treatment.
A hydrophilic passage 3C that does not undergo water repellency treatment is formed on the surface. The unit cell 1 configured as described above includes the porous support base material 3B.
A reservoir plate 6 made of carbon paper containing phosphoric acid is disposed on the side, and a gas impermeable separator 5 is disposed on the side of the porous support substrate 4B. A laminated fuel cell (stack) is formed by laminating the above-mentioned laminated body every plural layers with a liquid cooling type cooling plate (not shown) interposed therebetween.

【０００３】このように構成された燃料電池において
は、マトリックス２から電極触媒層３Ａ，４Ａにそれぞ
れ滲み出した液状のりん酸と、多孔質支持基材３Ｂ，４
Ｂを介してそれぞれ供給される反応ガスとが、電極触媒
層内で気，液，固三相界面を形成して電気化学反応を起
こすことにより発電が行われる。したがって、電気化学
反応が起こりやすいように、多孔質支持基材にはあらか
じめ液状のりん酸を含浸しておく必要がある。また、燃
料電池の運転中、酸化剤電極の電極触媒層４Ａには電気
化学反応に基づく生成水が生成され、水蒸気化した水分
が酸化剤とともに排出される。この時、生成水中にりん
酸が溶け込んで酸化剤とともに排出されるために、マト
リックス中のりん酸が徐々に減少してりん酸液の不足が
起こる。リザ−バプレ−ト６は不足したりん酸補給する
ために設けられており、親水性通路３Ｃを介してリザ−
バプレ−ト中のりん酸がマトリックスに移動し、さらに
マトリックス中をりん酸が不足する部分に向けて移動す
ることにより、マトリックス中のりん酸の不足が回避さ
れる。In the fuel cell thus constructed, the liquid phosphoric acid exuded from the matrix 2 into the electrode catalyst layers 3A and 4A, respectively, and the porous support substrates 3B and 4 are used.
Power generation is performed by the reaction gas supplied through B forming a gas-liquid three-phase interface in the electrode catalyst layer and causing an electrochemical reaction. Therefore, it is necessary to impregnate the porous support base material with liquid phosphoric acid in advance so that the electrochemical reaction easily occurs. Further, during operation of the fuel cell, generated water based on the electrochemical reaction is generated in the electrode catalyst layer 4A of the oxidant electrode, and water vaporized is discharged together with the oxidant. At this time, since phosphoric acid dissolves in the produced water and is discharged together with the oxidizing agent, the phosphoric acid in the matrix gradually decreases, and the phosphoric acid solution becomes insufficient. The reservoir plate 6 is provided to make up for the lacking phosphoric acid, and is reserved via the hydrophilic passage 3C.
Phosphoric acid in the matrix is avoided by migrating the phosphoric acid in the matrix to the matrix and further to the phosphoric acid-deficient portion in the matrix.

【０００４】図４は従来の燃料電池電極触媒層への電解
液含浸方法を示す斜視図であり、耐りん酸性を有する平
板７上に多孔質支持基材３Ｂ，４Ｂにあらかじめはっ水
処理した燃料電極３または４を、電極触媒層３Ａまたは
４Ａを上側にして載置し、さらにその上にあらかじめり
ん酸９を含ませたカ−ボンマット８を重ね、この状態で
全体を加熱し、粘度が低下して流動性を増したりん酸液
９を電極触媒層に転写含浸するよう構成した方法が知ら
れている。FIG. 4 is a perspective view showing a conventional method for impregnating a fuel cell electrode catalyst layer with an electrolytic solution. The porous supporting base materials 3B and 4B are preliminarily subjected to water repellency treatment on a flat plate 7 having phosphoric acid resistance. The fuel electrode 3 or 4 is placed with the electrode catalyst layer 3A or 4A on the upper side, and a carbon mat 8 preliminarily containing phosphoric acid 9 is laid on the fuel electrode 3 or 4, and the whole is heated in this state, and the viscosity is increased. A method is known in which the phosphoric acid solution 9 whose fluidity has been lowered to increase the fluidity is transferred and impregnated into the electrode catalyst layer.

【０００５】[0005]

【発明が解決しようとする課題】図５は電解液含浸方法
を含む単電池およびスタックの一連の組立工程を示す従
来の流れ図であり、スタックの組立工程の前工程には燃
料電極，酸化剤電極，マトリックス，およびリザ−バプ
レ−トそれぞれにりん酸液の含浸工程を含んでいる。こ
とに、両電極の電極触媒層にりん酸を含浸しようとする
場合、余分なりん酸が多孔質支持基材に付着して反応ガ
スの供給障害を起こすことの無いよう、手作業で細心の
注意を払って電極１枚に対し１枚のカ−ボンマットを重
ね合わせ、所定温度に加熱してりん酸液を転写含浸する
方法が採られており、これらの作業に多大な作業工数を
要するという問題がある。また、電極面積の広い電極で
は、面方向に温度分布の差を生じやすく、これが原因で
りん酸液の粘度および流動性にばらつきを生ずるため、
電極触媒層の面方向に一様な量のりん酸を含浸できず、
さらには単電池の出力特性のばらつきが大きくなるとい
う問題が発生する。さらに、電極触媒層に含浸されたり
ん酸が吸湿して電池性能に悪影響を及ぼすことを避ける
ため、含浸処理を終了した電極を乾燥炉に保管する必要
があり、そのための設備およびスペ−スを必要とする。FIG. 5 is a conventional flow chart showing a series of assembling steps of a unit cell and a stack including an electrolytic solution impregnation method, and a fuel electrode and an oxidizer electrode are provided in a step before the assembling step of the stack. The matrix, and the reservoir plate each include an impregnation step of a phosphoric acid solution. In particular, when attempting to impregnate the electrocatalyst layers of both electrodes with phosphoric acid, care must be taken by hand to prevent excess phosphoric acid from adhering to the porous support substrate and causing a reaction gas supply failure. Care is taken to superimpose one carbon mat on one electrode and heat it to a predetermined temperature to transfer and impregnate the phosphoric acid solution, which requires a great number of man-hours. There's a problem. Further, in an electrode having a wide electrode area, a difference in temperature distribution is likely to occur in the surface direction, which causes variations in viscosity and fluidity of the phosphoric acid solution.
Since it is impossible to impregnate a uniform amount of phosphoric acid in the plane direction of the electrode catalyst layer,
Furthermore, there arises a problem that variations in the output characteristics of the unit cells become large. Furthermore, in order to prevent the phosphoric acid impregnated in the electrode catalyst layer from absorbing moisture and adversely affecting the battery performance, it is necessary to store the electrode after the impregnation treatment in a drying furnace, and the equipment and space therefor must be maintained. I need.

【０００６】この発明の目的は、含浸工程の作業工数が
少なく、含浸処理後の保管が容易で、かつ含浸量のばら
つきの少ない燃料電池電極触媒層への電解液含浸方法を
得ることにある。An object of the present invention is to provide a method for impregnating a fuel cell electrode catalyst layer with an electrolyte solution, which requires a small number of man-hours in the impregnation step, is easy to store after the impregnation treatment, and has a small variation in the impregnation amount.

【０００７】[0007]

【課題を解決するための手段】上記課題を解決するため
に、この発明によれば、電解液をあらかじめ含浸したマ
トリックスと、その両面に電極触媒層が密接するように
それぞれ多孔質支持基材に支持された燃料電極および酸
化剤電極との積層体からなる単電池において、前記電極
触媒層に電解液を含浸する方法であって、単電池相互間
にガス不透過性のセパレ−タを，複数の単電池毎に液冷
式の冷却板を介装して単電池の積層体からなるスタック
を組立てた後、前記液冷式の冷却板に熱湯を通流してス
タックを所定温度に加熱し、流動性を増した前記マトリ
ックス中の電解液を電極触媒層に転写含浸することとす
る。In order to solve the above-mentioned problems, according to the present invention, a matrix preliminarily impregnated with an electrolytic solution and a porous support base material are provided so that electrode catalyst layers are in close contact with both surfaces of the matrix. A unit cell comprising a laminated body of a fuel electrode and an oxidizer electrode supported by a method, wherein the electrode catalyst layer is impregnated with an electrolytic solution, and a plurality of gas impermeable separators are provided between the unit cells. After assembling a stack consisting of a stack of single cells by interposing a liquid cooling type cooling plate for each unit cell, hot water is passed through the liquid cooling type cooling plate to heat the stack to a predetermined temperature, The electrolytic solution in the matrix having increased fluidity is transferred and impregnated into the electrode catalyst layer.

【０００８】また、液冷式の冷却板に通流する熱湯の温
度が１５０°C 以上、好ましくは１６０°C 前後である
こととする。Further, it is assumed that the temperature of the hot water flowing through the liquid cooling type cooling plate is 150 ° C. or higher, preferably around 160 ° C.

【０００９】さらに、単電池が親水性のカ−ボンペ−パ
−に電解液をあらかじめ含浸したリザ−バプレ−トを燃
料電極の多孔質支持基材とセパレ−タとの間に備え、転
写含浸により不足したマトリックス中の電解液を前記リ
ザ−バプレ−トから前記多孔質支持基材の親水性通路を
介して前記マトリックスに補給することとする。Further, the single cell is provided with a reservoir plate in which a hydrophilic carbon paper is impregnated with an electrolytic solution in advance between the porous supporting base material of the fuel electrode and the separator, and the transfer impregnation is carried out. Thus, the electrolyte solution deficient in the matrix is replenished to the matrix from the reservoir plate through the hydrophilic passage of the porous supporting substrate.

【００１０】[0010]

【作用】この発明の構成において、電極触媒層に電解液
を含浸する方法を、単電池相互間にガス不透過性のセパ
レ−タを，複数の単電池毎に液冷式の冷却板を介装して
単電池の積層体からなるスタックを組立てた後、液冷式
の冷却板に熱湯を通流してスタックを所定温度に加熱
し、流動性を増したマトリックス中の電解液を電極触媒
層に転写含浸するよう構成したことにより、スタックに
含まれる複数の単電池の電極触媒層への電解液の含浸を
１回の含浸工程により同時に行えるので、作業工数を大
幅に低減できるとともに、含浸処理した電極を乾燥炉内
に保管するも工程も不要になる。In the construction of the present invention, the method of impregnating the electrode catalyst layer with the electrolytic solution is carried out by using a gas-impermeable separator between the cells and a liquid cooling type cooling plate for each of the cells. After assembling a stack consisting of a stack of unit cells, the hot water is passed through a liquid cooling type cooling plate to heat the stack to a predetermined temperature, and the electrolytic solution in the matrix with increased fluidity is electrocatalyst layer. The transfer impregnation can be performed at the same time by impregnating the electrode catalyst layers of a plurality of unit cells included in the stack with the electrolytic solution in a single impregnation step. The electrode is stored in a drying oven, and no process is required.

【００１１】また、液冷式の冷却板に通流する熱湯の温
度が１５０°C 以上、好ましくは１６０°C 前後とすれ
ば、スタック内単電池の温度差を±５°C 程度の範囲内
に保持し、数十時間程度の作業時間で各単電池の電極触
媒層に均一にりん酸を含浸できるので、含浸量のばらつ
きに起因する電池性能の低下を阻止する機能が得られ
る。If the temperature of the hot water flowing through the liquid cooling type cooling plate is 150 ° C or higher, preferably around 160 ° C, the temperature difference between the cells in the stack is within a range of ± 5 ° C. Since the electrode catalyst layer of each unit cell can be uniformly impregnated with phosphoric acid in a working time of about several tens of hours, the function of preventing deterioration of cell performance due to variations in impregnation amount can be obtained.

【００１２】さらに、単電池が親水性のカ−ボンペ−パ
−に電解液をあらかじめ含浸したリザ−バプレ−トを燃
料電極の多孔質支持基材とセパレ−タとの間に備え、転
写含浸により不足したマトリックス中の電解液を前記リ
ザ−バプレ−トから前記多孔質支持基材の親水性通路を
介して前記マトリックスに補給するよう構成したことに
より、転写含浸によるマトリックス中の電解液の不足を
阻止し、燃料電池の発電性能への悪影響を排除する機能
が得られる。Further, a single cell is provided with a reservoir plate in which a hydrophilic carbon paper is pre-impregnated with an electrolytic solution between the porous supporting base material of the fuel electrode and the separator, and transfer impregnation is performed. The lack of electrolyte solution in the matrix due to transfer impregnation is constituted by replenishing the matrix from the reservoir plate through the hydrophilic passages of the porous supporting substrate with the electrolyte solution lacking in electrolyte solution due to transfer impregnation. And a function of preventing the adverse effect on the power generation performance of the fuel cell.

【００１３】[0013]

【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燃料電池電極触媒層
への電解液含浸方法における一連の工程を示す流れ図、
図２は実施例方法を説明するためのスタックの斜視図で
あり、従来の装置と同じ構成部分には同一参照符号を付
すことにより、重複した説明を省略する。図において、
燃料電極３および酸化剤電極４は多孔質支持基材３Ｂ，
４Ｂをはっ水処理した後電極触媒層３Ａ，４Ａに圧着
し、あらかじめりん酸を含浸したマトリックス２と積層
されて電極触媒層にりん酸が含浸されていない単電池１
が形成される。単電池１は、その両面にあらかじめ電解
液９を含浸したリザ−バプレ−ト６およびセパレ−タ５
を配し、さらに複数単電池ごとに液冷式の冷却板１２を
配して積層され、図２に示す端板１３および連結ボルト
１４からなる締付装置により所定の面圧が加えられるこ
とにより、単電池１の積層体からなるスタック１１が形
成される。EXAMPLES The present invention will be described below based on examples. FIG. 1 is a flow chart showing a series of steps in a method of impregnating a fuel cell electrode catalyst layer with an electrolyte solution according to an embodiment of the present invention,
FIG. 2 is a perspective view of a stack for explaining the method of the embodiment, and the same components as those of the conventional device are designated by the same reference numerals, and the duplicated description will be omitted. In the figure,
The fuel electrode 3 and the oxidant electrode 4 are made of a porous support base material 3B,
4B is hydrophobized and then pressure-bonded to the electrode catalyst layers 3A and 4A, which is laminated with a matrix 2 which is previously impregnated with phosphoric acid, so that the electrode catalyst layer is not impregnated with phosphoric acid 1
Is formed. The unit cell 1 has a reservoir plate 6 and a separator 5 both surfaces of which are previously impregnated with an electrolytic solution 9.
And a liquid cooling type cooling plate 12 is further arranged for each of a plurality of single cells to be laminated, and a predetermined surface pressure is applied by a tightening device including an end plate 13 and a connecting bolt 14 shown in FIG. A stack 11 including a stack of the unit cells 1 is formed.

【００１４】液冷式の冷却板１２は、これを積層面に沿
って貫通する複数の冷却パイプ１５を備え、燃料電池の
運転中は所定温度の冷却水を通流することにより発電生
成熱を排熱し、スタックを運転温度（例えば１９０°C
）に保持するよう機能する。実施例になる電解液含浸
方法では、この冷却パイプ１５に燃料電池の外部から熱
湯を通流循環し、スタック１１をりん酸の粘度が含浸に
好適な値に低下する所定温度に加熱する。このようにし
て粘度が低下し流動性を増したりん酸液は、マトリック
スに密接した電極触媒層３Ａ，４Ａに均一に転写含浸さ
れ、複数の単電池１の電極触媒層にりん酸を同時に転写
含浸することができる。The liquid-cooling type cooling plate 12 is provided with a plurality of cooling pipes 15 penetrating the cooling plate 12 along the stacking surface, and the cooling water of a predetermined temperature is passed during operation of the fuel cell to generate heat generated by power generation. Exhaust heat and run the stack at operating temperature (eg 190 ° C
) To hold. In the electrolytic solution impregnation method according to the embodiment, hot water is circulated through the cooling pipe 15 from the outside of the fuel cell to heat the stack 11 to a predetermined temperature at which the viscosity of phosphoric acid decreases to a value suitable for impregnation. The phosphoric acid solution with reduced viscosity and increased fluidity is uniformly transferred and impregnated into the electrode catalyst layers 3A and 4A that are in close contact with the matrix, and phosphoric acid is transferred simultaneously to the electrode catalyst layers of the plurality of unit cells 1. It can be impregnated.

【００１５】一方、リザ−バプレ−ト６および多孔質支
持基材の親水性通路３Ｃは、燃料電池の運転中、発電生
成水にりん酸が溶解して反応ガス中に飛散するために、
マトリックス２に生ずるりん酸の不足を補給するために
設けられるものであるが、りん酸の転写含浸過程でマト
リックス中に生ずるりん酸の不足に対しても有効に機能
し、マトリックス中のりん酸の不足による電池性能の低
下を未然に防止することができる。On the other hand, in the hydrophilic passage 3C of the reservoir plate 6 and the porous supporting substrate, phosphoric acid is dissolved in the water generated by the power generation and scattered in the reaction gas during the operation of the fuel cell.
The matrix 2 is provided to replenish the shortage of phosphoric acid generated in the matrix 2, but it also functions effectively against the shortage of phosphoric acid generated in the matrix during the transfer impregnation process of phosphoric acid. It is possible to prevent deterioration of battery performance due to a shortage.

【００１６】実施例になる電解液含浸方法において、冷
却パイプ１５に通流する熱湯の温度を１６０°C 一定に
保ち、スタック各部に位置する単電池の温度分布を測定
した結果、１６０±５°C の範囲に収まることが確認さ
れた、また、この状態で各単電池の開回路電圧の時間変
化を測定した結果、５０時間経過時点で各単電池の開回
路電圧は９８０ｍｖ前後に安定した。さらに、含浸処理
を終了したスタックの試運転を行った結果、単電池間の
出力特性のばらつきも少なく、所望の出力特性が得られ
た。これらの検証試験結果から、この発明の実施例にな
る電解液含浸方法によれば、所望の電解液含浸性能と、
燃料電池のむらのない出力特性が得られることが実証さ
れた。なお熱湯の温度は含浸作業による電極等の劣化を
阻止する意味で１６０°C 程度とすることが好ましい
が、含浸時間の都合により１５０〜１９０°C の範囲で
任意に選択されてよく、図示しない燃料電池の冷却水循
環系を利用して所望の加熱温度が得られる。In the electrolytic solution impregnation method according to the embodiment, the temperature of the hot water flowing through the cooling pipe 15 was kept constant at 160 ° C., and the temperature distribution of the cells located in each part of the stack was measured. As a result, 160 ± 5 ° It was confirmed that it was within the range of C 2, and as a result of measuring the time change of the open circuit voltage of each unit cell in this state, the open circuit voltage of each unit cell was stable at about 980 mv after 50 hours. Further, as a result of performing a trial run of the stack after the impregnation treatment, there was little variation in the output characteristics between the single cells, and the desired output characteristics were obtained. From these verification test results, according to the electrolytic solution impregnation method according to the embodiment of the present invention, the desired electrolytic solution impregnation performance,
It was demonstrated that a uniform output characteristic of the fuel cell can be obtained. The temperature of the hot water is preferably set to about 160 ° C in order to prevent the deterioration of the electrodes and the like due to the impregnation work, but it may be arbitrarily selected within the range of 150 to 190 ° C depending on the impregnation time and is not shown. A desired heating temperature can be obtained by utilizing the cooling water circulation system of the fuel cell.

【００１７】なお、図２において、反応ガスの給排用マ
ニホ−ルド１６は、これを取り付けない状態で含浸処理
を行ってもよいが、マニホ−ルドに例えば乾燥窒素を封
入または循環した状態で含浸処理を行うことにより、り
ん酸液の吸湿を防ぎ、かつ電極等の劣化を防止できる利
点が得られる。In FIG. 2, the reaction gas supply / discharge manifold 16 may be impregnated without attaching it, but the manifold may be filled or circulated with dry nitrogen, for example. By carrying out the impregnation treatment, it is possible to obtain an advantage that it is possible to prevent the phosphoric acid solution from absorbing moisture and prevent the deterioration of the electrodes and the like.

【００１８】[0018]

【発明の効果】この発明は前述のように、電極触媒層に
電解液を含浸する方法を、単電池相互間にガス不透過性
のセパレ−タを，複数の単電池毎に液冷式の冷却板を介
装して単電池の積層体からなるスタックを組立てた後、
液冷式の冷却板に熱湯を通流してスタックを所定温度に
加熱し、流動性を増したマトリックス中の電解液を電極
触媒層に転写含浸するよう構成した。その結果、スタッ
クに含まれる複数の単電池の電極触媒層への電解液の含
浸を１回の含浸工程により同時に行えるので、従来一
つ，一つの電極に電解液を含浸する手作業の殆ど全てを
排除して作業工数を大幅に低減できる燃料電池電極触媒
層への電解液含浸方法を提供することができる。また、
マトリックス，リザ−バプレ−ト，親水性通路など燃料
電池の運転に不可欠な構成要素をりん酸の含浸処理に活
用できるので、従来必要とした転写含浸用のカ−ボンマ
ットや平板，あるいは防湿用の乾燥炉等の製造設備およ
び作業スペ−スが不要になり、作業工数の低減と併せて
大きな経済的メリットを有する燃料電池電極触媒層への
電解液含浸方法を提供することができる。As described above, the present invention employs a method of impregnating an electrode catalyst layer with an electrolytic solution, in which a gas-impermeable separator is provided between the unit cells and a liquid-cooling type separator is used for each unit cell. After assembling a stack consisting of a stack of unit cells with a cooling plate interposed,
Hot water was passed through a liquid cooling type cooling plate to heat the stack to a predetermined temperature, and the electrode catalyst layer was impregnated with the electrolytic solution in the fluidized matrix by transfer impregnation. As a result, it is possible to simultaneously impregnate the electrode catalyst layers of a plurality of unit cells included in the stack with the electrolytic solution in a single impregnation step. It is possible to provide a method for impregnating a fuel cell electrode catalyst layer with an electrolytic solution, which can eliminate the above-mentioned problem and greatly reduce the number of working steps. Also,
The matrix, reservoir plate, hydrophilic passages, and other essential components for fuel cell operation can be utilized for impregnating phosphoric acid. It is possible to provide a method of impregnating a fuel cell electrode catalyst layer with an electrolytic solution, which does not require a manufacturing facility such as a drying furnace and a work space, and has a great economic merit as well as a reduction in the number of work steps.

【００１９】また、液冷式の冷却板に通流する熱湯の温
度が１５０°C 以上、好ましくは１６０°C 前後とする
よう構成した。その結果、スタック内単電池の温度差を
±５°C 程度の範囲内に保持して含浸むらのない電極触
媒層が得られるとともに、数十時間程度の含浸時間で各
単電池の電極触媒層に均一にりん酸を含浸できるので、
含浸量のばらつきに起因する電池性能の低下を阻止さ
れ、優れた出力特性を有する燃料電池が得られる燃料電
池電極触媒層への電解液含浸方法を提供することができ
る。The temperature of the hot water flowing through the liquid cooling type cooling plate is set to 150 ° C. or higher, preferably around 160 ° C. As a result, the temperature difference of the unit cells in the stack is kept within a range of about ± 5 ° C to obtain an electrode catalyst layer without unevenness of impregnation, and the electrode catalyst layer of each unit cell can be obtained with the impregnation time of about tens of hours. Since it can be uniformly impregnated with phosphoric acid,
It is possible to provide a method of impregnating a fuel cell electrode catalyst layer with an electrolyte solution in which a decrease in cell performance due to variations in impregnation amount is prevented and a fuel cell having excellent output characteristics is obtained.

【００２０】さらに、単電池が親水性のカ−ボンペ−パ
−に電解液をあらかじめ含浸したリザ−バプレ−トを燃
料電極の多孔質支持基材とセパレ−タとの間に備え、転
写含浸により不足したマトリックス中の電解液をリザ−
バプレ−トから多孔質支持基材の親水性通路を介してマ
トリックスに補給するよう構成したことにより、転写含
浸によるマトリックス中の電解液の不足を阻止し、燃料
電池の発電性能への悪影響を排除できる利点が得られ
る。Further, a single cell is provided with a reservoir plate in which a hydrophilic carbon paper is pre-impregnated with an electrolytic solution between the porous supporting base material of the fuel electrode and the separator, and transfer impregnation is carried out. The electrolyte solution in the matrix that was insufficient due to
By replenishing the matrix from the vapor through the hydrophilic passages of the porous support substrate, it prevents shortage of electrolyte in the matrix due to transfer impregnation and eliminates adverse effects on the power generation performance of the fuel cell. The advantage that can be obtained is obtained.

【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燃料電池電極触媒層へ
の電解液含浸方法における一連の工程を示す流れ図FIG. 1 is a flow chart showing a series of steps in a method for impregnating a fuel cell electrode catalyst layer with an electrolyte solution according to an embodiment of the present invention.

【図２】実施例方法を説明するためのスタックの斜視図FIG. 2 is a perspective view of a stack for explaining an embodiment method.

【図３】りん酸形燃料電池の単電池構造を示す展開図FIG. 3 is a development view showing a unit cell structure of a phosphoric acid fuel cell.

【図４】従来の燃料電池電極触媒層への電解液含浸方法
を示す斜視図FIG. 4 is a perspective view showing a conventional method for impregnating a fuel cell electrode catalyst layer with an electrolytic solution.

【図５】電解液含浸方法を含むスタックの一連の組立工
程を示す従来の流れ図FIG. 5 is a conventional flow chart showing a series of assembly steps of a stack including an electrolytic solution impregnation method.

【符号の説明】[Explanation of symbols]

１ 単電池 ２ マトリックス ３ 燃料電極 ３Ａ 電極触媒層 ３Ｂ 多孔質支持基材 ４ 酸化剤電極 ４Ａ 電極触媒層 ４Ｂ 多孔質支持基材 ５ セパレ−タ ６ リザ−バプレ−ト ７ 平板 ８ カ−ボンマット ９ りん酸（液） １１ スタック １２ 冷却板 １３ 端板 １４ 締付ボルト １５ 冷却パイプ １６ マニホ−ルド 1 Cell 2 Matrix 3 Fuel electrode 3A Electrocatalyst layer 3B Porous support base material 4 Oxidizer electrode 4A Electrocatalyst layer 4B Porous support base material 5 Separator 6 Reservoir plate 7 Flat plate 8 Carbon mat 9 Phosphorus Acid (liquid) 11 Stack 12 Cooling plate 13 End plate 14 Tightening bolt 15 Cooling pipe 16 Manifold

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】電解液をあらかじめ含浸したマトリックス
と、その両面に電極触媒層が密接するようにそれぞれ多
孔質支持基材に支持された燃料電極および酸化剤電極と
の積層体からなる単電池において、前記電極触媒層に電
解液を含浸する方法であって、単電池相互間にガス不透
過性のセパレ−タを，複数の単電池毎に液冷式の冷却板
を介装して単電池の積層体からなるスタックを組立てた
後、前記液冷式の冷却板に熱湯を通流してスタックを所
定温度に加熱し、流動性を増した前記マトリックス中の
電解液を電極触媒層に転写含浸することを特徴とする燃
料電池電極触媒層への電解液含浸方法。1. A unit cell comprising a matrix, which is preliminarily impregnated with an electrolytic solution, and a stack of a fuel electrode and an oxidizer electrode, each of which is supported on a porous support substrate so that electrode catalyst layers are in close contact with both surfaces of the matrix. A method for impregnating the electrode catalyst layer with an electrolytic solution, wherein a gas-impermeable separator is provided between the unit cells and a liquid cooling type cooling plate is provided for each unit cell. After assembling the stack consisting of the laminated body, the hot water is passed through the liquid cooling type cooling plate to heat the stack to a predetermined temperature, and the electrocatalyst in the matrix having increased fluidity is transferred and impregnated into the electrode catalyst layer. A method of impregnating a fuel cell electrode catalyst layer with an electrolytic solution, comprising: 【請求項２】液冷式の冷却板に通流する熱湯の温度が１
５０°C 以上、好ましくは１６０°C 前後であることを
特徴とする請求項１記載の燃料電池電極触媒層への電解
液含浸方法。2. The temperature of hot water flowing through a liquid cooling type cooling plate is 1
The method for impregnating an electrolyte with a fuel cell electrode catalyst layer according to claim 1, wherein the temperature is 50 ° C or higher, preferably around 160 ° C. 【請求項３】単電池が親水性のカ−ボンペ−パ−に電解
液をあらかじめ含浸したリザ−バプレ−トを燃料電極の
多孔質支持基材とセパレ−タとの間に備え、転写含浸に
より不足したマトリックス中の電解液を前記リザ−バプ
レ−トから前記多孔質支持基材の親水性通路を介して前
記マトリックスに補給することを特徴とする請求項１記
載の燃料電池電極触媒層への電解液含浸方法。3. A single cell is provided with a reservoir plate in which a hydrophilic carbon paper is pre-impregnated with an electrolytic solution between a porous supporting base material of a fuel electrode and a separator, and transfer impregnation is performed. 2. The fuel cell electrode catalyst layer according to claim 1, wherein the electrolyte solution deficient in the matrix is replenished to the matrix from the reservoir plate through the hydrophilic passages of the porous supporting substrate. Method of impregnating electrolyte.