JPH05335030A - Method for enhancing performance of fuel cell - Google Patents
Method for enhancing performance of fuel cellInfo
- Publication number
- JPH05335030A JPH05335030A JP4165470A JP16547092A JPH05335030A JP H05335030 A JPH05335030 A JP H05335030A JP 4165470 A JP4165470 A JP 4165470A JP 16547092 A JP16547092 A JP 16547092A JP H05335030 A JPH05335030 A JP H05335030A
- Authority
- JP
- Japan
- Prior art keywords
- cathode
- anode
- fuel cell
- electrolyte
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims description 15
- 230000002708 enhancing effect Effects 0.000 title 1
- 239000007789 gas Substances 0.000 claims abstract description 66
- 239000003792 electrolyte Substances 0.000 claims abstract description 65
- 238000010248 power generation Methods 0.000 claims abstract description 35
- 230000001590 oxidative effect Effects 0.000 claims abstract description 22
- 238000009826 distribution Methods 0.000 claims abstract description 12
- 239000011261 inert gas Substances 0.000 claims abstract description 6
- 230000003647 oxidation Effects 0.000 claims abstract description 5
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 5
- 230000014759 maintenance of location Effects 0.000 claims description 3
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 abstract description 4
- 210000004027 cell Anatomy 0.000 description 40
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 8
- 230000007423 decrease Effects 0.000 description 5
- 239000002737 fuel gas Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000010406 cathode material Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 210000003771 C cell Anatomy 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000036647 reaction Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Landscapes
- Fuel Cell (AREA)
Abstract
(57)【要約】
【目的】 燃料電池の発電性能を向上させる。
【構成】 電解質を含浸させた電解質板１をカソード２
とアノード３の両電極で両面から挾持させてなるセルＣ
をセパレータ４を介して積層させる。燃料電池の性能が
低下すると、カソード２側へ供給する酸化ガスを停止
し、その代りに不活性ガス又は還元性ガスを供給する。
カソード２の表面状態を、運転時の酸化状態から還元状
態に処理する。カソード２の表面状態を変えて電解質５
の配分を制御させて燃料電池の発電性能を向上させる。
(57) [Summary] [Purpose] To improve the power generation performance of fuel cells. [Constitution] Electrolyte plate 1 impregnated with electrolyte is cathode 2
A cell C sandwiched between both electrodes of the anode and the anode 3
Are laminated via the separator 4. When the performance of the fuel cell deteriorates, the oxidizing gas supplied to the cathode 2 side is stopped, and instead, an inert gas or a reducing gas is supplied.
The surface state of the cathode 2 is processed from the oxidation state during operation to the reduction state. Electrolyte 5 by changing the surface condition of cathode 2
Control the distribution of the fuel cell to improve the power generation performance of the fuel cell.
Description
【０００１】[0001]
【産業上の利用分野】本発明は燃料の有する化学エネル
ギーを直接電気エネルギーに変換するエネルギー部門で
用いる燃料電池の発電性能を向上させるための方法に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving the power generation performance of a fuel cell used in the energy sector for directly converting chemical energy of fuel into electric energy.
【０００２】[0002]
【従来の技術】燃料電池のうち、溶融炭酸塩型燃料電池
は、図８に概略を示す如く、電解質として溶融炭酸塩を
多孔質物質にしみ込ませてなる電解質板（タイル）１
を、カソード（酸素極）２とアノード（燃料極）３の両
電極で両面から挟み、カソード２側に酸化ガス（Ｏ2 、
ＣＯ2 、Ｎ2 等を含む）ＯＧを供給すると共にアノード
３側に還元性ガスである燃料ガス（Ｈ2 、ＣＯ、Ｃ
Ｏ2 、Ｈ2 Ｏ等を含む）ＦＧを供給することにより、カ
ソード２側では、 ＣＯ2 ＋1/2 Ｏ2 ＋２ｅ- →ＣＯ3 -- の反応を行わせて炭酸イオンＣＯ3 --を生成させるよう
にし、一方、アノード３側では、上記炭酸イオンＣＯ3
--が電解質板１中を泳動してアノード３側へ達すること
により該炭酸イオンＣＯ3 --と燃料ガスが接触して、 ＣＯ3 --＋Ｈ2 →ＣＯ2 ＋Ｈ2 Ｏ＋２ｅ- ＣＯ3 --＋ＣＯ→２ＣＯ2 ＋２ｅ- の反応が行われ、このアノード３側での反応と上記カソ
ード２側での反応によって発電が行われるようにしたも
のを１セルＣとし、各セルＣをセパレータ４を介し多層
に積層してスタックとするようにしてある。2. Description of the Related Art Among fuel cells, a molten carbonate fuel cell is an electrolyte plate (tile) 1 made by impregnating a molten carbonate as an electrolyte into a porous material as shown in FIG.
Is sandwiched between both electrodes of a cathode (oxygen electrode) 2 and an anode (fuel electrode) 3, and an oxidizing gas (O 2 ,
OG containing CO 2 , N 2 etc. is supplied and fuel gas (H 2 , CO, C) which is a reducing gas is supplied to the anode 3 side.
By supplying FG (including O 2 , H 2 O, etc.), on the cathode 2 side, a reaction of CO 2 +1/2 O 2 + 2e − → CO 3 − is performed to generate a carbonate ion CO 3 − . On the other hand, on the side of the anode 3, the carbonate ion CO 3
- electrolyte plate 1 Medium carbon acid by reaching the were run anode 3 side ion CO 3 - and the fuel gas is in contact, CO 3 - + H 2 → CO 2 + H 2 O + 2e - CO 3 - The reaction of + CO → 2CO 2 + 2e − is performed, and one in which the power generation is performed by the reaction on the anode 3 side and the reaction on the cathode 2 side is defined as one cell C, and each cell C is connected via the separator 4. It is made to be laminated by stacking in multiple layers.
【０００３】上記従来の溶融炭酸塩型燃料電池で用いら
れる電極のうち、カソード２は、Ｎｉ多孔質体を酸化さ
せてＮｉＯとしたものが素材とされており、又、アノー
ド３は、Ｎｉ又はＮｉ合金粉の成形体を還元雰囲気中で
焼結してなる多孔質体が用いられている。Of the electrodes used in the conventional molten carbonate fuel cell, the cathode 2 is made of NiO by oxidizing a Ni porous body, and the anode 3 is made of Ni or Ni. A porous body formed by sintering a compact of Ni alloy powder in a reducing atmosphere is used.
【０００４】上記溶融炭酸塩型燃料電池は、運転開始前
に、電解質板１の製造時に用いた有機結合剤の除去を行
う脱脂処理や、電解質としての炭酸塩（Ｌｉ2 ＣＯ3 、
Ｋ2ＣＯ3 ）を電解質板１に含浸保持させる含浸処理が
行われ、更には、カソードの酸化作用とリチウム化が行
われ、かかる処理が終了することによって燃料電池は運
転できる状態になる。The molten carbonate fuel cell described above has a degreasing treatment for removing the organic binder used during the production of the electrolyte plate 1 before starting the operation, and a carbonate (Li 2 CO 3) as an electrolyte.
K 2 CO 3 ) is impregnated and held in the electrolyte plate 1, and further, the cathode is oxidized and lithiated, and the fuel cell can be operated by completing the treatment.
【０００５】又、通常、燃料電池の発電出力、このう
ち、電池電流は、電極面積等によって運転初期に予め決
められ、燃料電池の運転中にその電圧が極端に低下しな
い範囲で、カソード２側へ供給されるガスの利用率やア
ノード３側へ供給されるガスの利用率をコントロールし
て発電効率を向上させるようにする工夫が考えられてい
る。[0007] Usually, the power output of the fuel cell, of which the cell current is predetermined in the initial stage of operation by the electrode area and the like, and within the range where the voltage does not drop extremely during the operation of the fuel cell, the cathode 2 side It is considered to improve the power generation efficiency by controlling the utilization rate of the gas supplied to the anode 3 and the utilization rate of the gas supplied to the anode 3 side.
【０００６】[0006]
【発明が解決しようとする課題】ところが、燃料電池の
発電性能は、種々の原因で低下することがある。その原
因として、前記したカソード側、アノード側のガス利用
率の変化のほかに、カソード２とアノード３の電極性能
の低下、電解質板１の内部抵抗の増加等があげられる。
特に、電解質としての溶融炭酸塩が多孔質体のカソード
２に過剰に入り込んでカソード２の孔を占有した状態に
なり電池反応が不充分となったり、電解質板１の電解質
が欠乏して、電解質板１の内部抵抗が増加すると、燃料
電池の発電性能が低下して来る。一方、アノード３側で
は、空孔の形状が変化して電解質の保持能力が低下し、
多孔質体アノード３中の電解質が消失し、燃料電池の発
電性能が低下して来ることが実験によって確認されてい
る。However, the power generation performance of the fuel cell may deteriorate due to various causes. In addition to the above-mentioned changes in the gas utilization rates on the cathode side and the anode side, the causes thereof are a decrease in the electrode performance of the cathode 2 and the anode 3, an increase in the internal resistance of the electrolyte plate 1, and the like.
In particular, molten carbonate as an electrolyte excessively enters the cathode 2 of the porous body to occupy the pores of the cathode 2 and the battery reaction becomes insufficient, or the electrolyte of the electrolyte plate 1 is deficient. When the internal resistance of the plate 1 increases, the power generation performance of the fuel cell decreases. On the other hand, on the anode 3 side, the shape of the pores changes, and the electrolyte retention capacity decreases,
It has been confirmed by experiments that the electrolyte in the porous anode 3 disappears and the power generation performance of the fuel cell deteriorates.
【０００７】従来、かかる場合の対抗策は提案されてい
ない。Conventionally, no countermeasure has been proposed for such a case.
【０００８】そこで、本発明は、燃料電池の発電性能が
低下したときに、カソード側が原因のときはカソード表
面のぬれ性を下げるようにし、又、アノード側が原因の
ときはアノード表面のぬれ性を向上させるようにして電
池の運転状態を保持したまま発電性能の向上を図るよう
にしようとするものである。Therefore, the present invention reduces the wettability of the cathode surface when the power generation performance of the fuel cell is deteriorated when the cathode side is the cause, and the wettability of the anode surface when the anode side is the cause. It is intended to improve the power generation performance while maintaining the operating state of the battery.
【０００９】[0009]
【課題を解決するための手段】本発明は、上記課題を解
決するために、燃料電池の発電性能が低下したときに、
カソードへ供給するガスを酸化ガスから不活性ガスも
しくは還元性ガスに変更して、カソード表面を還元処理
し、カソードに過剰に入り込んでいた電解質を抜き出し
て電解質板の方へ移動させ、カソード表面のぬれ性を変
えて電解質の再配分を行い発電性能を向上させるように
する方法とする。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides
The gas supplied to the cathode is changed from an oxidizing gas to an inert gas or a reducing gas, the cathode surface is subjected to a reduction treatment, and the electrolyte that has excessively entered the cathode is extracted and moved to the electrolyte plate. A method of changing the wettability and redistributing the electrolyte to improve the power generation performance.
【００１０】又、アノードへ供給するガスを停止し
て、アノード側へカソード側から空気を導くようにする
か、又はアノード側へ還元性ガスに代えて酸化性ガスを
供給してアノード表面を酸化処理し、アノード表面の空
隙率を高めて電解質をアノード表面にとり込み、アノー
ド表面のぬれ性を変えて電解質の再配分を行い、発電性
能を向上させるようにする方法とすることもできる。Further, the gas supplied to the anode is stopped so that air is introduced from the cathode side to the anode side, or an oxidizing gas is supplied to the anode side instead of the reducing gas to oxidize the anode surface. Alternatively, the porosity of the anode surface may be increased to incorporate the electrolyte into the anode surface, and the wettability of the anode surface may be changed to redistribute the electrolyte to improve the power generation performance.
【００１１】又、カソード側又はアノード側へのガス
の供給を停止又は上記のガスに変更した後に、電池に電
流を流して、カソード側ではカソード素材中の酸素を使
ってカソード表面を還元処理し、アノード側ではアノー
ド中の水素を使ってアノード表面を酸化処理して、カソ
ード又はアノードの表面状態を制御するようにしてもよ
い。Further, after the gas supply to the cathode side or the anode side is stopped or changed to the above gas, an electric current is passed through the cell, and the cathode surface is subjected to reduction treatment using oxygen in the cathode material on the cathode side. On the anode side, hydrogen in the anode may be used to oxidize the surface of the anode to control the surface condition of the cathode or the anode.
【００１２】、、は単独に行っても、と又は
と、ととを同時に行ってもよい。[0012] ,, and may be performed independently, and and or and may be performed simultaneously.
【００１３】[0013]
【作用】カソードへ供給する通常の酸化性ガスを停止し
て、不活性ガスもしくは還元性ガスを流すと、カソード
表面が還元処理されてカソード表面のぬれ性が低下し
て、カソード中の電解質がカソード表面から電解質板の
方向へ移動させられ、電解質の配分が変えられる。これ
により電解質板の電解質の不足は解消されて電解質自体
の内部抵抗が減少すると同時に、カソードの電極性能も
改善され、発電性能の向上が図れる。[Function] When the normal oxidizing gas supplied to the cathode is stopped and an inert gas or a reducing gas is caused to flow, the cathode surface is subjected to a reduction treatment, the wettability of the cathode surface is lowered, and the electrolyte in the cathode is reduced. It is moved from the cathode surface towards the electrolyte plate, changing the distribution of the electrolyte. As a result, the shortage of the electrolyte in the electrolyte plate is eliminated, the internal resistance of the electrolyte itself is reduced, and at the same time, the performance of the cathode electrode is improved and the power generation performance is improved.
【００１４】アノード側へ供給する還元性ガスを停止
し、カソード側から空気をアノードに導くか、あるいは
アノード側へ酸化ガスを供給すると、アノード表面が酸
化処理されるが、このとき、アノード表面のぬれ性が高
められて電解質のアノード表面への取り込みが行われて
電極中の電解質の欠乏が解消し、発電性能が向上させら
れる。When the reducing gas supplied to the anode side is stopped and air is introduced from the cathode side to the anode or an oxidizing gas is supplied to the anode side, the anode surface is oxidized. At this time, The wettability is enhanced, and the electrolyte is taken into the anode surface to eliminate the lack of electrolyte in the electrode and improve the power generation performance.
【００１５】上記ガスの切り換えに加えて電流を流す
と、カソード側ではカソードの材質（ＮｉＯ）中の酸素
が電池反応で使われて還元処理され、又、アノード側で
はアノード中のＮｉが使われて酸化処理される。すなわ
ち、カソードやアノードの表面状態が電流で制御される
ことになり、電解質の配分が制御できる。When a current is passed in addition to the above gas switching, oxygen in the cathode material (NiO) is used in the cell reaction for reduction treatment on the cathode side, and Ni in the anode is used on the anode side. Is oxidized. That is, the surface conditions of the cathode and the anode are controlled by the current, and the distribution of the electrolyte can be controlled.
【００１６】[0016]
【実施例】以下、本発明の実施例を図面を参照して説明
する。Embodiments of the present invention will be described below with reference to the drawings.
【００１７】図１及び図２は本発明の一実施例を示すも
ので、図８に示す従来の溶融炭酸塩型燃料電池の場合と
同様に、多孔質物質に電解質として溶融炭酸塩をしみ込
ませてなる電解質板１をカソード２とアノード３の両電
極で両面から挟み、カソード２側に酸化ガス（Ｏ2 、Ｃ
Ｏ2 等）ＯＧを供給すると共に、アノード３側に還元性
のガスである燃料ガス（Ｈ2 、ＣＯ、ＣＯ2 等）ＦＧを
供給するようにしたものを１セルＣとして、該セルＣを
セパレータ４を介して積層するようにしてある構成にお
いて、燃料電池の発電性能が低下したときに、短時間で
カソード２の表面のみを還元処理してカソード２の表面
状態を制御させ電解質の配分を変えて発電性能を向上さ
せるようにする。FIGS. 1 and 2 show an embodiment of the present invention. As in the case of the conventional molten carbonate fuel cell shown in FIG. 8, a porous carbonate is impregnated with molten carbonate as an electrolyte. The electrolyte plate 1 composed of the two is sandwiched between both electrodes of the cathode 2 and the anode 3, and the oxidizing gas (O 2 , C
O 2 and the like) OG, and a fuel gas (H 2 , CO, CO 2 and the like) FG which is a reducing gas to the anode 3 side is defined as one cell C. In the structure in which the separators 4 are laminated via the separator 4, when the power generation performance of the fuel cell is deteriorated, only the surface of the cathode 2 is reduced in a short time to control the surface condition of the cathode 2 to distribute the electrolyte. Change to improve power generation performance.
【００１８】詳述すると、燃料電池の発電性能（電池電
圧）が、初期の性能に比して、たとえば、３０ｍＶ〜４
０ｍＶ下がっているときは性能低下と判断し、本発明の
方法を実施する。この場合に、図１（イ）の如く、カソ
ード２側へ通常流している酸化ガスＯＧ中の空気Ｏ2 の
供給を停止し、この空気に代えて図１（ロ）の如く、Ｎ
2 、ＣＯ2 、Ｈ2 の如き不活性ガスもしくは還元性ガス
を、発電時のガス量に相当する量だけ流通ガスとして供
給させるようにする。これにより、カソード２の表面は
還元状態に処理される。この処理時間は、燃料電池の状
態にもよるが、１５分〜３０分間とか、３０分〜２時間
の比較的短時間として、カソード２の表面のみが処理さ
れるようにし、内部まで処理されることがないようにす
る。More specifically, the power generation performance (cell voltage) of the fuel cell is, for example, 30 mV to 4 mV compared to the initial performance.
When the voltage drops by 0 mV, it is determined that the performance is degraded, and the method of the present invention is carried out. In this case, as shown in FIG. 1A, the supply of the air O 2 in the oxidizing gas OG that is normally flowing to the cathode 2 side is stopped, and the air is replaced with N as shown in FIG.
2, an inert gas such as CO2, H2 or a reducing gas is supplied as a distribution gas in an amount corresponding to the amount of gas at the time of power generation. As a result, the surface of the cathode 2 is processed into a reduced state. Although this treatment time depends on the state of the fuel cell, it is set to a relatively short time of 15 minutes to 30 minutes or 30 minutes to 2 hours so that only the surface of the cathode 2 is treated and the inside is treated. Try not to.
【００１９】ＮｉＯを素材とするカソード２が、その表
面の還元処理でカソード２の表面がＮｉＯからＮｉに戻
されると、これまで図２（イ）の如くカソード２に過剰
に入り込んでいた電解質５がカソード２表面から抜けて
図２（ロ）の如く電解質板１の方へ移動する。これによ
りカソード２表面では含まれる電解質５の量が減って過
剰状態が解消され、カソード２表面への電解質の配分が
コントロールされる。同時に、電解質板１にはカソード
２表面から抜けた電解質５が入って電解質板１の電解質
の欠乏が解消され、電解質板１自体の内部抵抗が減少す
る。その結果、燃料電池の大幅な発電性能の向上が図れ
る。When the surface of the cathode 2 made of NiO is returned from NiO to Ni by the reduction treatment of the surface of the cathode 2, the electrolyte 5 which has been excessively introduced into the cathode 2 as shown in FIG. Escape from the surface of the cathode 2 and move toward the electrolyte plate 1 as shown in FIG. As a result, the amount of the electrolyte 5 contained on the surface of the cathode 2 is reduced, the excess state is eliminated, and the distribution of the electrolyte to the surface of the cathode 2 is controlled. At the same time, the electrolyte 5 that has escaped from the surface of the cathode 2 enters the electrolyte plate 1 to eliminate the lack of electrolyte in the electrolyte plate 1, and the internal resistance of the electrolyte plate 1 itself decreases. As a result, the power generation performance of the fuel cell can be significantly improved.
【００２０】上記カソード２の表面を還元処理をする前
としたときの発電性能（電池電圧）の変化は、図３に示
す如き結果となることが実験により確認された。It was confirmed by experiments that the change in power generation performance (battery voltage) before the surface of the cathode 2 was subjected to the reduction treatment resulted in the result shown in FIG.
【００２１】カソード２の表面状態を、還元状態にして
ぬれ性を下げ、これにより電解質の配分をコントロール
することによって燃料電池の発電性能の向上が図れる
と、次に、カソード２側への不活性ガスもしくは還元性
ガスに代えて通常の酸化ガスＯＧの供給に戻し、燃料電
池の運転を継続させるようにする。When the surface condition of the cathode 2 is reduced to reduce the wettability and the distribution of the electrolyte is controlled by this, the power generation performance of the fuel cell can be improved. Instead of the gas or the reducing gas, the normal supply of the oxidizing gas OG is returned to continue the operation of the fuel cell.
【００２２】なお、上記実施例は、カソード２へ供給す
るガスを不活性又は還元性のガスに切り換えてカソード
表面を還元処理する場合であるが、これに代えて、カソ
ード２へのガスの供給を停止して又は、ガスを切り換え
てから電流を流すことによってもカソード２の表面状態
を還元状態にすることができる。In the above embodiment, the gas supplied to the cathode 2 is switched to an inert or reducing gas to reduce the surface of the cathode, but instead of this, the gas is supplied to the cathode 2. Alternatively, the surface state of the cathode 2 can be brought to the reduced state by stopping the above or switching the gas and then passing an electric current.
【００２３】すなわち、カソード２への通常の酸化ガス
の供給を停止した状態で定格の1/100 〜1/20程度の電流
を通常の負荷回路又は外部から通電して流すと、カソー
ド２の素材であるＮｉＯのＯが使われてＮｉに戻され、
還元処理される。これにより前記実施例の場合と同様に
カソード２の表面のぬれ性が下がり、電解質の配分が制
御されて発電性能を向上させることができる。That is, when a current of about 1/100 to 1/20 of the rated value is passed from a normal load circuit or from outside with the supply of the normal oxidizing gas to the cathode 2 stopped, the material of the cathode 2 is changed. O of NiO is used and returned to Ni,
It is reduced. As a result, the wettability of the surface of the cathode 2 is reduced, and the distribution of the electrolyte is controlled, so that the power generation performance can be improved, as in the case of the above embodiment.
【００２４】次に、図４は本発明の更に別の実施例を示
すもので、燃料電池の発電性能を向上させるため、アノ
ード３へのガスを酸化性のガスに切り換えてアノード３
の表面状態を短時間（１５分〜３０分間又は３０分〜２
時間）で酸化状態に処理し、電解質の配分を制御するよ
うにしたものである。Next, FIG. 4 shows another embodiment of the present invention. In order to improve the power generation performance of the fuel cell, the gas for the anode 3 is switched to an oxidizing gas and the anode 3 is changed.
Surface condition for a short time (15 minutes to 30 minutes or 30 minutes to 2
It is treated in an oxidized state for a period of time) to control the distribution of the electrolyte.
【００２５】これには２通りの方法があり、１つは、ア
ノード３へ供給される通常の還元性のガス（Ｈ2 、Ｃ
Ｏ、ＣＯ2 等）を停止し、カソード２側から空気Ｏ2 を
アノード３側へ導き、アノード３表面のＮｉを酸化させ
てＮｉＯとする酸化処理する方法であり、他の１つは、
アノード３へ供給されるガスを、通常の還元性ガスから
不活性又は酸化性のガス（Ｎ2 、Ｏ2 、ＣＯ2 等）の単
独又は混合ガスに切り換えて定常運転時と同じガス量を
流し、アノード３の表面を酸化状態に処理させる方法で
ある。There are two methods for this, and the first method is to use ordinary reducing gases (H 2 and C) supplied to the anode 3.
O, CO 2, etc.), and air O 2 is introduced from the cathode 2 side to the anode 3 side to oxidize Ni on the surface of the anode 3 to NiO, and the other one is
The gas supplied to the anode 3 is switched from an ordinary reducing gas to an inert or oxidizing gas (N 2 , O 2 , CO 2, etc.) alone or as a mixed gas, and the same amount of gas as in steady operation is flowed. , The surface of the anode 3 is treated in an oxidized state.
【００２６】上記いずれの方法によっても、アノード３
の表面が酸化処理されるとき、アノード３の表面は膨張
し、次に、酸化処理後にＮｉＯからＮｉにもどすにアノ
ード３の表面は収縮して、アノード３の表面に微細なひ
び割れ（クラック）が生じて残り、これが電解質の保持
能力を高めることになり、電解質がアノード表面に引き
込まれて電解質の配分が変えられ、ぬれ性が向上させら
れて発電性能を向上させることができることになる。上
記アノード３の表面を酸化処理する前と酸化処理した後
の発電性能（電池電圧）の変化は、図５に示す如き結果
となることが実験により確認されている。By any of the above methods, the anode 3
When the surface of the anode 3 is oxidized, the surface of the anode 3 expands, and then the surface of the anode 3 contracts when returning from NiO to Ni after the oxidation treatment, and fine cracks are formed on the surface of the anode 3. It is generated and remains, which enhances the electrolyte retention ability, the electrolyte is drawn to the anode surface, the distribution of the electrolyte is changed, the wettability is improved, and the power generation performance can be improved. It has been confirmed by experiments that the change in the power generation performance (battery voltage) before and after the surface of the anode 3 is subjected to the oxidation treatment has a result as shown in FIG.
【００２７】又、上記実施例において、アノード３側へ
のガスを切り換えてアノード３の表面を酸化処理する方
法に加えて、電流を流してアノード３の表面を酸化処理
することもできる。Further, in the above embodiment, in addition to the method of oxidizing the surface of the anode 3 by switching the gas to the side of the anode 3, the surface of the anode 3 can be oxidized by applying a current.
【００２８】この場合は、アノード３へのガスの供給を
停止又は、ガスを切り換えて、定格の1/10〜1/2 程度の
電流を通常の負荷回路又は外部から通電して流してアノ
ード３側の材料中のＮｉを酸化して、アノード３表面を
酸化状態にしてアノード３のＮｉ多孔質体を酸化させて
ＮｉＯとするようにして、前記実施例の場合と同様にア
ノード表面のぬれ性を向上させて発電性能を向上させる
ようにする。In this case, the supply of gas to the anode 3 is stopped or the gas is switched, and a current of about 1/10 to 1/2 of the rating is passed from a normal load circuit or the outside to flow the current to the anode 3 Ni in the material on the side is oxidized to make the surface of the anode 3 in an oxidized state to oxidize the Ni porous body of the anode 3 to form NiO, and the wettability of the anode surface is the same as in the above-mentioned embodiment. To improve power generation performance.
【００２９】なお、上述した本発明の各実施例は、燃料
電池の運転中は勿論のこと、運転前でも実施できること
は当然であるが、燃料電池として運転できる状態になっ
ていることが前提であることは勿論である。The above-mentioned embodiments of the present invention can be carried out not only during the operation of the fuel cell but also before the operation, but it is premised that the fuel cell can be operated. Of course there is.
【００３０】又、燃料電池の発電性能は、燃料電池の運
転温度によっても変動することが実験の結果確認されて
いる。この場合、アノード３側は、反応が発熱反応であ
るため、図６（イ）（ロ）（ハ）に示す如く、アノード
側の過電圧（反応による電圧損失）の温度依存性はあま
りないが、カソード側では、反応が吸熱反応であるた
め、図７（イ）（ロ）（ハ）に示す如く、燃料電池の運
転温度が変化すると、カソード側過電圧（反応による電
圧損失）の温度依存性がかなり大きいことがわかる。図
６及び図７において、温度以外の条件はすべて同一であ
る。It has been confirmed as a result of experiments that the power generation performance of the fuel cell also varies depending on the operating temperature of the fuel cell. In this case, since the reaction on the anode 3 side is an exothermic reaction, the overvoltage (voltage loss due to the reaction) on the anode side has little temperature dependency, as shown in FIGS. Since the reaction on the cathode side is an endothermic reaction, as shown in FIGS. 7 (a), (b) and (c), if the operating temperature of the fuel cell changes, the temperature dependence of the cathode side overvoltage (voltage loss due to the reaction) will change. You can see that it is quite large. 6 and 7, the conditions other than the temperature are all the same.
【００３１】したがって、図７からわかるように、燃料
電池の発電性能（電池電圧）は燃料電池の運転温度で変
動するものであり、発電性能が低下した場合、燃料電池
の温度を変化させることにより発電性能の低下がどちら
の電極の要因によるものか判別できる。Therefore, as can be seen from FIG. 7, the power generation performance (cell voltage) of the fuel cell fluctuates depending on the operating temperature of the fuel cell. When the power generation performance deteriorates, the temperature of the fuel cell is changed. It is possible to determine which electrode causes the decrease in power generation performance.
【００３２】[0032]
【発明の効果】以上述べた如く、本発明の燃料電池の性
能向上方法によれば、カソードへのガスを酸化性ガスか
ら不活性又は還元性ガスに代えるか、又はカソードへの
ガスを停止して電流を流すことによりカソード電極の表
面状態を還元状態に処理してカソードに過剰に入ってい
た電解質を放出させて電解質板の方へ移動させるように
するので、カソード表面の電解質の配分を変えることが
できて燃料電池の発電性能（電池電圧）を大幅に向上さ
せることができると共に、電解質板の内部抵抗を減少で
きて燃料電池の発電性能を向上させることができ、且つ
カソードの表面のみを還元処理することから、短時間で
処理ができる、という優れた効果を奏し得られ、又、ア
ノードへのガスを停止してカソード側の空気を導くか、
あるいはアノードへのガスを還元性ガスから不活性又は
酸化性ガスに代えるか、又はアノードへのガスを停止し
て電流を流すことによってアノード電極の表面状態を酸
化状態に処理してアノード表面の空隙率を高めてぬれ性
を向上させるようにすることにより、カソード表面の電
解質の配分を変えることができて燃料電池の発電性能を
向上させることができる、という優れた効果を奏し得
る。As described above, according to the fuel cell performance improving method of the present invention, the gas to the cathode is changed from the oxidizing gas to the inert or reducing gas, or the gas to the cathode is stopped. Current is applied to treat the surface of the cathode electrode in a reduced state to release the excess electrolyte in the cathode and move it toward the electrolyte plate, changing the distribution of the electrolyte on the cathode surface. It is possible to significantly improve the power generation performance (cell voltage) of the fuel cell, reduce the internal resistance of the electrolyte plate, and improve the power generation performance of the fuel cell. From the reduction treatment, it is possible to obtain an excellent effect that the treatment can be performed in a short time, and also, to stop the gas to the anode to introduce the air on the cathode side,
Alternatively, the gas for the anode is changed from a reducing gas to an inert or oxidizing gas, or the gas for the anode is stopped and an electric current is passed to treat the surface state of the anode electrode as an oxidized state to form voids on the anode surface. By increasing the rate to improve the wettability, it is possible to exert an excellent effect that the distribution of the electrolyte on the cathode surface can be changed and the power generation performance of the fuel cell can be improved.
【図１】本発明の一実施例の概略を示すもので、（イ）
は通常の運転状態を示す概略断面図、（ロ）はカソード
表面を処理するときの状態を示す概略断面図である。FIG. 1 shows an outline of an embodiment of the present invention, in which (a)
Is a schematic cross-sectional view showing a normal operation state, and (b) is a schematic cross-sectional view showing a state when the cathode surface is treated.
【図２】図１のカソードと電解質板の拡大を示すもの
で、（イ）はカソードに電解質が過剰に入り込んでいる
状態を示す概略断面図、（ロ）はカソード表面から電解
質が抜けた状態を示す概略断面図である。FIG. 2 is an enlarged view of the cathode and the electrolyte plate in FIG. 1, where (a) is a schematic cross-sectional view showing a state in which the electrolyte has excessively entered the cathode, and (b) is a state in which the electrolyte has escaped from the cathode surface. It is a schematic sectional drawing which shows.
【図３】カソード表面の還元処理前後の電池性能の変化
を示す図である。FIG. 3 is a diagram showing changes in cell performance before and after a reduction treatment on a cathode surface.
【図４】本発明の他の実施例を示すもので、（イ）は通
常運転時のアノード表面の状態を示す概略断面図、
（ロ）はアノード表面に電解質が移った状態を示す概略
断面図である。FIG. 4 shows another embodiment of the present invention, in which (a) is a schematic cross-sectional view showing the state of the anode surface during normal operation,
(B) is a schematic cross-sectional view showing a state in which the electrolyte is transferred to the anode surface.
【図５】アノード表面の酸化処理前後の電池性能の変化
を示す図である。FIG. 5 is a diagram showing changes in battery performance before and after oxidation treatment on the anode surface.
【図６】アノード側過電圧の温度依存性を過電圧と電流
密度との関係で示すもので、（イ）は温度５８０℃のと
きの図、（ロ）は温度５５５℃のときの図、（ハ）は温
度６１２℃のときの図である。FIG. 6 shows the temperature dependence of the overvoltage on the anode side by the relationship between the overvoltage and the current density. (A) is a diagram when the temperature is 580 ° C., (b) is a diagram when the temperature is 555 ° C. ) Is a diagram at a temperature of 612 ° C.
【図７】カソード側過電圧の温度依存性を過電圧と電流
密度との関係で示すもので、（イ）は温度５５５℃のと
きの図、（ロ）は温度６００℃のときの図、（ハ）は温
度６４４℃のときの図である。FIG. 7 shows the temperature dependence of the cathode-side overvoltage in terms of the relationship between the overvoltage and the current density. (A) is a diagram when the temperature is 555 ° C., (b) is a diagram when the temperature is 600 ° C., ) Is a diagram at a temperature of 644 ° C.
【図８】従来の溶融炭酸塩型燃料電池の一例を示す概略
断面図である。FIG. 8 is a schematic sectional view showing an example of a conventional molten carbonate fuel cell.
１ 電解質板 ２ カソード ３ アノード ４ セパレータ ５ 電解質 Ｃ セル ＯＧ 酸化ガス ＦＧ 燃料ガス（還元性ガス） Ｎ2 不活性ガス1 Electrolyte Plate 2 Cathode 3 Anode 4 Separator 5 Electrolyte C Cell OG Oxidizing Gas FG Fuel Gas (Reducing Gas) N 2 Inert Gas
Claims (6)
両面から挟み、カソード側に酸化ガスを供給すると共に
アノード側に還元性ガスを供給するようにしたセルをセ
パレータを介し積層するようにしてある燃料電池の発電
性能が低下したときに、上記カソードの表面状態を還元
状態に処理し、該カソードに過剰に入り込んでいる電解
質をカソード表面から電解質板の方へ移動させてカソー
ド表面の電解質配分を制御することを特徴とする燃料電
池の性能向上方法。1. A cell in which an electrolyte plate is sandwiched between electrodes of a cathode and an anode from both sides and an oxidizing gas is supplied to the cathode side and a reducing gas is supplied to the anode side is laminated with a separator interposed therebetween. When the power generation performance of the fuel cell deteriorates, the surface state of the cathode is treated to a reduced state, and the electrolyte excessively entering the cathode is moved from the cathode surface to the electrolyte plate to distribute the electrolyte on the cathode surface. A fuel cell performance improving method characterized by controlling.
もしくは還元性ガスに代えてカソードの表面状態を還元
状態に処理する請求項１記載の燃料電池の性能向上方
法。2. The method of improving the performance of a fuel cell according to claim 1, wherein the surface of the cathode is treated in a reducing state by replacing the gas for the cathode with an oxidizing gas from an inert gas or a reducing gas.
流を流してカソードの表面状態を還元状態に処理する請
求項１記載の燃料電池の性能向上方法。3. The method for improving the performance of a fuel cell according to claim 1, wherein the supply of an oxidizing gas to the cathode is stopped and a current is passed to treat the surface state of the cathode in a reduced state.
両面から挟み、カソード側に酸化ガスを供給すると共に
アノード側に還元性ガスを供給するようにしたセルをセ
パレータを介し積層するようにしてある燃料電池の発電
性能が低下したときに、上記アノードの表面状態を酸化
状態に処理し、該アノード表面のぬれ性を高めて電解質
の配分を制御し、電解質の保持能力を増すことを特徴と
する燃料電池の性能向上方法。4. An electrolyte plate is sandwiched between electrodes of a cathode and an anode from both sides, and cells in which an oxidizing gas is supplied to the cathode side and a reducing gas is supplied to the anode side are laminated through a separator. When the power generation performance of the fuel cell deteriorates, the surface state of the anode is treated to an oxidation state, the wettability of the anode surface is enhanced to control the distribution of the electrolyte, and the electrolyte retention capacity is increased. Fuel cell performance improvement method.
し、カソード側からアノード側へ空気を導くか、又はア
ノード側へ不活性もしくは酸化性ガスを供給してアノー
ドの表面状態を酸化状態に処理する請求項４記載の燃料
電池の性能向上方法。5. The supply of reducing gas to the anode is stopped and air is introduced from the cathode side to the anode side, or an inert or oxidizing gas is supplied to the anode side to bring the surface state of the anode into an oxidized state. The method for improving the performance of a fuel cell according to claim 4, wherein the treatment is performed.
し、電流を流してアノードの表面状態を酸化状態に処理
する請求項４記載の燃料電池の性能向上方法。6. The method for improving the performance of a fuel cell according to claim 4, wherein the supply of the reducing gas to the anode is stopped, and a current is passed to treat the surface state of the anode in an oxidized state.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4165470A JPH05335030A (en) | 1992-06-02 | 1992-06-02 | Method for enhancing performance of fuel cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4165470A JPH05335030A (en) | 1992-06-02 | 1992-06-02 | Method for enhancing performance of fuel cell |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05335030A true JPH05335030A (en) | 1993-12-17 |
Family
ID=15813029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4165470A Pending JPH05335030A (en) | 1992-06-02 | 1992-06-02 | Method for enhancing performance of fuel cell |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05335030A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0750171A (en) * | 1994-06-20 | 1995-02-21 | Hitachi Ltd | Fused-salt type fuel cell power generating plant |
| JP2008034305A (en) * | 2006-07-31 | 2008-02-14 | Tokyo Gas Co Ltd | Anode reduction method for solid oxide fuel cells |
| JP2009032490A (en) * | 2007-07-26 | 2009-02-12 | Sony Corp | Fuel cell system and electronic equipment |
| JP2011119035A (en) * | 2009-11-30 | 2011-06-16 | Toshiba Corp | Direct methanol fuel cell and electronic device |
-
1992
- 1992-06-02 JP JP4165470A patent/JPH05335030A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0750171A (en) * | 1994-06-20 | 1995-02-21 | Hitachi Ltd | Fused-salt type fuel cell power generating plant |
| JP2008034305A (en) * | 2006-07-31 | 2008-02-14 | Tokyo Gas Co Ltd | Anode reduction method for solid oxide fuel cells |
| JP2009032490A (en) * | 2007-07-26 | 2009-02-12 | Sony Corp | Fuel cell system and electronic equipment |
| JP2011119035A (en) * | 2009-11-30 | 2011-06-16 | Toshiba Corp | Direct methanol fuel cell and electronic device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101296431B1 (en) | Battery and method for operating a battery | |
| KR20080083112A (en) | Bifunctional air electrode | |
| KR101863845B1 (en) | Rechargeable energy storage unit | |
| US11081713B2 (en) | Fuel cell activation method | |
| JPH1145733A (en) | Polymer electrolyte fuel cell | |
| JP2009289681A (en) | Method of cleaning fuel cell | |
| US9620833B2 (en) | Electric energy store | |
| JPH05335030A (en) | Method for enhancing performance of fuel cell | |
| JPH0622144B2 (en) | Fuel cell | |
| JP5025389B2 (en) | Control method for fuel cell power generation system and fuel cell power generation system | |
| US5641328A (en) | Fuel cell cathodes | |
| JPS63170865A (en) | Molten carbonate fuel cell and its operating method | |
| JP4678115B2 (en) | Operation method and operation system of solid oxide fuel cell | |
| JPS6010566A (en) | How to operate a fuel cell | |
| JP2766185B2 (en) | Molten salt fuel cell power plant | |
| JP2007128790A (en) | Fuel cell control method and control device therefor | |
| JP3852177B2 (en) | Method for treating cathode for molten carbonate fuel cell | |
| KR101253956B1 (en) | Method for manufacturing metal supported solid oxide fuel cell | |
| JPS63170866A (en) | Molten salt fuel cell power generation plant | |
| JP2009231081A (en) | Fuel cell | |
| JPH0471168A (en) | Fuel cell power generation plant | |
| JP2022023494A (en) | Fuel cell pretreatment method | |
| JPH06223837A (en) | Fuel cell with molten carbonate | |
| JP2023166706A (en) | fuel cell system | |
| JP5256630B2 (en) | Operation method of fuel cell |