JPH11162483A - Solid electrolyte fuel cell - Google Patents

Solid electrolyte fuel cell

Info

Publication number
JPH11162483A
JPH11162483A JP9322562A JP32256297A JPH11162483A JP H11162483 A JPH11162483 A JP H11162483A JP 9322562 A JP9322562 A JP 9322562A JP 32256297 A JP32256297 A JP 32256297A JP H11162483 A JPH11162483 A JP H11162483A
Authority
JP
Japan
Prior art keywords
fuel cell
solid electrolyte
oxygen
protective film
cell according
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
Application number
JP9322562A
Other languages
Japanese (ja)
Inventor
Tomofumi Miyashita
朋史 宮下
Hisashi Suwahara
久 諏訪原
Satoshi Seike
聡 清家
Yoshitaka Noguchi
孝卓 野口
Chieko Imazawa
智恵子 今澤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Meidensha Corp
Meidensha Electric Manufacturing Co Ltd
Original Assignee
Meidensha Corp
Meidensha Electric Manufacturing Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Meidensha Corp, Meidensha Electric Manufacturing Co Ltd filed Critical Meidensha Corp
Priority to JP9322562A priority Critical patent/JPH11162483A/en
Publication of JPH11162483A publication Critical patent/JPH11162483A/en
Pending legal-status Critical Current

Links

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

Abstract

PROBLEM TO BE SOLVED: To prevent a gas leak from occurring even if a solid electrolyte is cracked. SOLUTION: A dense, mixed conductive, thin protective film 12 which contains NiO having conductivity for ions and electrons is formed on the upper face of a porous metal substrate 11 having mechanical strength to serve as an anode electrode. A solid electrolyte 13 made of SDC or YSZ insulative against electrons is formed on the upper face of the thin protective film 12. A cathode electrode 14 made of La0.85 Sr0.15 MnO3 is formed on the cathode side of the solid electrolyte 13.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】この発明は、固体電解質のア
ノード側に緻密で、かつイオンと電子に対して導電性の
ある保護膜を設けた固体電解質型燃料電池に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolyte fuel cell provided with a dense protective film on the anode side of a solid electrolyte and conductive to ions and electrons.

【０００２】[0002]

【従来の技術】固体電解質型燃料電池（以下ＳＯＦＣと
称す）の原理構成を示す概略構成図を図６に示す。図６
において、酸素イオン電導性のある固体電解質５１の図
示両側にペロブスカイトから成る多孔質の酸素極５２
(カソード)とＮｉ−ＹＳＺサーメットから成る多孔質の
水素極５３(アノード)を取り付ける。酸素極５２側の酸
素供給室５４に酸素ガスＯ2もしくは空気を流し込む
と、酸素極５２で酸素分子は酸素電極の触媒５５によっ
て酸素イオンＯ2-となる。次式にその反応式を示す。2. Description of the Related Art FIG. 6 is a schematic configuration diagram showing the principle configuration of a solid oxide fuel cell (hereinafter referred to as SOFC). FIG.
In FIG. 2, a porous oxygen electrode 52 made of perovskite is provided on both sides of a solid electrolyte 51 having oxygen ion conductivity in the drawing.
(Cathode) and a porous hydrogen electrode 53 (anode) made of Ni-YSZ cermet. When oxygen gas O 2 or air flows into the oxygen supply chamber 54 on the oxygen electrode 52 side, oxygen molecules are converted to oxygen ions O 2− by the catalyst 55 of the oxygen electrode at the oxygen electrode 52. The following equation shows the reaction formula.

【０００３】 １／２Ｏ2 ＋ ２ｅ- → Ｏ2- …… (１) 酸素イオンＯ2-は酸素イオン電導性のある固体電解質５
１を拡散しながら水素極５３に達する。水素極５３側に
は水素ガスもしくは天然ガスなどの燃料ガスが燃料ガス
供給室５６に流し込まれていて、固体電解質５１を通過
してきた酸素イオンＯ2-は水素電極の触媒５７の助けを
借りて燃料ガスと反応して水蒸気や二酸化炭素となって
燃料ガス中に除去される。次式は酸素イオンが水素ガス
と反応するときの反応式である。[0003] 1 / 2O 2 + 2e - → O 2- ...... (1) oxygen ions O 2- oxygen ion conductivity of a solid electrolyte 5
1 reaches the hydrogen electrode 53 while diffusing. A fuel gas such as hydrogen gas or natural gas is poured into the fuel gas supply chamber 56 on the hydrogen electrode 53 side, and the oxygen ions O 2− that have passed through the solid electrolyte 51 are assisted by the catalyst 57 of the hydrogen electrode. It reacts with the fuel gas to become water vapor or carbon dioxide and is removed from the fuel gas. The following equation is a reaction equation when oxygen ions react with hydrogen gas.

【０００４】 Ｈ2 ＋ Ｏ2- → Ｈ2Ｏ ＋ ２ｅ- …… (２) なお、固体電解質５１には酸素イオンは通すけれども、
電子には絶縁である物質が使用される。５８は負荷で、
この負荷５８はカソード・アノード間に接続される。H 2 + O 2− → H 2 O + 2e − (2) Although oxygen ions pass through the solid electrolyte 51,
A substance that is insulating is used for electrons. 58 is a load,
This load 58 is connected between the cathode and the anode.

【０００５】前記ＳＯＦＣで使用される固体電解質５１
の材料には、イットリウムなどの酸化物をジルコニアに
固溶させて生成された安定化ジルコニア(ＹＳＺ)を使用
したものが多い。このＹＳＺを使用した燃料電池の動作
は約１０００℃の高温となるために、ＳＯＦＣの構成材
料には耐熱性のあるもの例えばセラミックス等の耐熱材
料を使用する。しかし、セラミックスは高価で加工しに
くい問題がある。そこで、電池の動作温度を下げて電池
構成材料の耐熱性を低下させる試みがなされている。そ
の手段としては固体電解質の材料に例えばＣｅＯ2，Ｂ
ｉ2Ｏ3等の物質を使用して燃料電池の動作温度を約７０
０〜８００℃にしたものが研究されている。これら固体
電解質は水素極雰囲気等の還元雰囲気において還元され
てしまう問題があるけれども、動作温度をＹＳＺの場合
よりも低くできる利点がある。この為、最近ではＹＳＺ
の代替材料にＣｅＯ2系の電解質を使用した燃料電池が
使用されるようになってきた。[0005] The solid electrolyte 51 used in the SOFC
In many cases, stabilized zirconia (YSZ) produced by dissolving an oxide such as yttrium in zirconia is used. Since the operation of the fuel cell using YSZ is at a high temperature of about 1000 ° C., a heat-resistant material such as ceramics is used as the material of the SOFC. However, there is a problem that ceramics are expensive and difficult to process. Therefore, attempts have been made to lower the operating temperature of the battery to lower the heat resistance of the battery constituent materials. As the means, for example, CeO 2 , B
Using a material such as i 2 O 3 to increase the operating temperature of the fuel cell to about 70
Temperatures between 0 and 800 ° C have been studied. Although these solid electrolytes have the problem of being reduced in a reducing atmosphere such as a hydrogen electrode atmosphere, they have the advantage that the operating temperature can be lower than in the case of YSZ. For this reason, recently YSZ
Fuel cells using CeO 2 -based electrolytes as alternative materials have come to be used.

【０００６】[0006]

【発明が解決しようとする課題】上述したＳＯＦＣは固
体電解質に薄膜のセラミックを使用しているため、固体
電解質が脆く割れやすい問題がある。上述したＳＯＦＣ
において、固体電解質が図７に示すようにひび割れ４１
が発生すると、アノード側の水素ガスがカソード側の酸
素側に漏れてＳＯＦＣとしての性能がなくなってしまう
ために、固体電解質の取り替えを行わなければならない
問題が発生する。なお、図７において、４２は固体電解
質、４３はアノード電極、４４はカソード電極である。Since the above-mentioned SOFC uses a thin-film ceramic as the solid electrolyte, there is a problem that the solid electrolyte is brittle and easily cracked. SOFC mentioned above
In FIG. 7, the solid electrolyte is cracked 41 as shown in FIG.
When this occurs, the hydrogen gas on the anode side leaks to the oxygen side on the cathode side and the performance as an SOFC is lost, so that a problem that the solid electrolyte must be replaced occurs. In FIG. 7, reference numeral 42 denotes a solid electrolyte, 43 denotes an anode electrode, and 44 denotes a cathode electrode.

【０００７】上記のように固体電解質が脆く割れやすい
状況にあるのは、特にＳＯＦＣを動作温度８００〜１０
００℃で運転し、定期点検などのために、ＳＯＦＣを室
温まで冷却する際に熱膨張変化による機械的な内部応力
が生じたときである。このため、ＳＯＦＣを実用化する
のは極めて難しい状況下にある。[0007] As described above, the solid electrolyte is in a state of being brittle and easily broken, particularly when the SOFC is operated at an operating temperature of 800 to 10
This is when mechanical internal stress is generated due to a change in thermal expansion when the SOFC is cooled to room temperature for operation at 00 ° C. and periodic inspection. Therefore, it is extremely difficult to put the SOFC into practical use.

【０００８】通常、固体電解質としては上述したように
ＹＳＺやＣｅＯ2系のＳＤＣ（Ｓｍ2Ｏ3 Ｄoped Ｃｅ
Ｏ2）である。これらの特徴において、ＹＳＺは機械的
強度が強く、イオン導電率が小さく、ＳＤＣは機械的強
度が弱く、イオン導電率が大きいことである。このため
に、ＳＯＦＣの開発の主流は現在電気的特性を落として
も機械的強度を高める方向で行われており、固体電解質
にはＹＳＺが使用されている。しかしながら、ＹＳＺを
使用した固体電解質においても割れないようにするには
技術的に極めて難しい。As described above, YSZ or CeO 2 -based SDC (Sm 2 O 3 Doped Ce) is usually used as the solid electrolyte.
O 2 ). In these characteristics, YSZ has high mechanical strength and low ionic conductivity, and SDC has low mechanical strength and high ionic conductivity. For this reason, the mainstream of the development of SOFCs is currently performed in the direction of increasing the mechanical strength even if the electric characteristics are lowered, and YSZ is used as the solid electrolyte. However, it is technically extremely difficult to prevent cracking even in a solid electrolyte using YSZ.

【０００９】この発明は上記の事情に鑑みてなされたも
ので、固体電解質のアノード側に緻密で、かつイオンと
電子に対して導電性のある保護膜を設けて固体電解質が
割れてもガス漏れが生じないようにした固体電解質型燃
料電池を提供することを課題とする。The present invention has been made in view of the above circumstances, and provides a dense protective film on the anode side of the solid electrolyte and conductive to ions and electrons. It is an object of the present invention to provide a solid oxide fuel cell in which generation of a fuel cell is prevented.

【００１０】[0010]

【課題を解決するための手段】この発明は、上記の課題
を達成するために、固体電解質に水素極と酸素極を形成
し、水素ガス若しくは天然ガスなどの燃料ガスを水素極
側に、酸素ガス若しくは空気を酸素極側に流して両極間
に電力を発生させる固体電解質型燃料電池において、前
記固体電解質の水素極側に、イオンと電子に対して導電
性のある混合導電性の緻密な保護膜を形成し、また、前
記固体電解質はＣｅＯ2を主たる成分とする酸化物で構
成する。なお、前記保護膜はＮｉなどの水素に対して触
媒作用のある物質を混入して形成し、かつ、酸素イオン
導電性のあるペロブスカイトに＋３価の希土類元素を含
む酸化物をドープして作製した酸素欠損型のペロブスカ
イト型結晶構造の酸化物からなることを特徴とする。According to the present invention, in order to achieve the above object, a hydrogen electrode and an oxygen electrode are formed in a solid electrolyte, and a fuel gas such as hydrogen gas or natural gas is supplied to the hydrogen electrode side with an oxygen electrode. In a solid oxide fuel cell in which gas or air flows to the oxygen electrode side to generate electric power between the two electrodes, in the hydrogen electrode side of the solid electrolyte, a mixed conductive dense protection that is conductive to ions and electrons. A film is formed, and the solid electrolyte is composed of an oxide containing CeO 2 as a main component. The protective film was formed by mixing a substance having a catalytic action on hydrogen such as Ni, and was prepared by doping an oxide containing a +3 valent rare earth element into perovskite having oxygen ion conductivity. It is characterized by being composed of an oxide having an oxygen-deficient perovskite crystal structure.

【００１１】[0011]

【発明の実施の形態】以下この発明の実施の形態を図面
に基づいて説明する。図１において、１０は固体電解質
型燃料電池のセルの構造を示すもので、１１はアノード
電極となる機械的強度のある多孔質な金属基板であり、
この基板１１の上面に緻密で、かつイオンと電子に対し
て導電性のあるＮｉＯを含む混合導電性の薄い保護膜１
２を形成する。この薄い保護膜１２の上面には電子に対
して絶縁となるＳＤＣやＹＳＺからなる固体電解質１３
を設ける。固体電解質１３のカソード側には、Ｌａ0・85
Ｓｒ0・15 ＭｎＯ3からなるカソード電極１４を形成す
る。なお、混合導電性の薄い保護膜１２は、ＣｕＯなど
を成分に含ませて半セラミック、半金属にて作製でき
る。Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 10 denotes a cell structure of a solid oxide fuel cell, and reference numeral 11 denotes a porous metal substrate having mechanical strength serving as an anode electrode;
A thin mixed conductive thin protective film 1 containing NiO, which is dense and conductive to ions and electrons, is formed on the upper surface of the substrate 11.
Form 2 On the upper surface of the thin protective film 12, a solid electrolyte 13 made of SDC or YSZ which is insulated from electrons is provided.
Is provided. On the cathode side of the solid electrolyte 13, La 0.85
The cathode electrode 14 made of Sr 0 .15 MnO 3 is formed. The mixed conductive thin protective film 12 can be made of semi-ceramic or semi-metal with CuO or the like included in the components.

【００１２】上記のように構成したセル１０をＮ2雰囲
気中にさらして温度を８００℃まで上昇させた後、室温
まで下げる冷熱サイクルを２０回程繰り返した。その結
果、図２に示すように固体電解質１３にはひび割れ１５
が発生した。しかし、固体電解質１３のカソード側には
混合導電性の薄い保護膜１２があり、この保護膜１２が
金属基板１１を良好に覆っており、保護膜１２には、ひ
び割れが発生しなかった。この理由は、混合導電性の薄
い保護膜１２は半金属、半セラミックであるので、金属
との相性が格段に向上しているためである。これによ
り、固体電解質１３にひび割れが発生してもガス漏れを
確実に防止することができるようになり、良好なＳＯＦ
Ｃを構成することができるようになる。After the cell 10 constructed as described above was exposed to an N 2 atmosphere to raise the temperature to 800 ° C., a cooling / heating cycle for lowering the temperature to room temperature was repeated about 20 times. As a result, as shown in FIG.
There has occurred. However, a thin mixed conductive thin protective film 12 was provided on the cathode side of the solid electrolyte 13, the protective film 12 satisfactorily covered the metal substrate 11, and the protective film 12 did not crack. The reason is that the mixed conductive thin protective film 12 is a semi-metal or semi-ceramic, so that the compatibility with the metal is remarkably improved. As a result, even if cracks occur in the solid electrolyte 13, gas leakage can be reliably prevented, and good SOF
C can be configured.

【００１３】上記のように構成されたＳＯＦＣにおい
て、混合導電性の薄い保護膜１２の材料成分としては、
小さい酸素イオン活性化エネルギと、高温での水素に対
する耐久性が要求されるため、その材料を選択するに当
たり以下の２点を留意して材料を開発した。In the SOFC constructed as described above, the material components of the mixed conductive thin protective film 12 include:
Since low oxygen ion activation energy and durability against hydrogen at high temperatures are required, the following two points were taken into consideration when selecting the material, and the material was developed.

【００１４】第１留意点：還元に対して強い事が既に実
証されている酸素イオン導電性材料を主たる成分とす
る。例えば、ＺｒＯ2，ＣｅＯ2系材料は還元に対して耐
久性があることが既に知られている。First point: An oxygen ion conductive material whose resistance to reduction has already been demonstrated is used as a main component. For example, it is already known that ZrO 2 and CeO 2 based materials have durability against reduction.

【００１５】第２留意点：イオンの活性化エネルギは、
結晶構造に強く依存する。例えば、蛍石型の結晶構造の
酸素イオン導電体であるＺｒＯ2系、ＣｅＯ2系、Ｂｉ2
Ｏ3系の活性化エネルギは０.７ｅＶ前後から１ｅＶ前後
である。それに対して酸素イオン欠損型のペロブスカイ
ト型結晶構造を持つＹＢＣＯ（ＹＢａ2Ｃｕ3Ｏ7）は、
０.３ｅＶ前後という低い活性化エネルギを持つ。この
材料の構造は、酸素イオン空孔の濃度が大きく、２つの
酸素イオン空孔間の距離が短いことが特徴で、その結晶
構造例を図３に示す。Second point: The activation energy of ions is
It depends strongly on the crystal structure. For example, ZrO 2 -based, CeO 2 -based, Bi 2 , which are oxygen ion conductors having a fluorite-type crystal structure
The activation energy of the O 3 system is about 0.7 eV to about 1 eV. On the other hand, YBCO (YBa 2 Cu 3 O 7 ) having an oxygen ion deficient perovskite crystal structure is
It has a low activation energy of about 0.3 eV. The structure of this material is characterized in that the concentration of oxygen ion vacancies is large and the distance between two oxygen ion vacancies is short. An example of the crystal structure is shown in FIG.

【００１６】上記第１、第２留意点から、還元に強い材
料ＺｒＯ2系、ＣｅＯ2系を元にして、結晶構造を変化さ
せてイオンの活性化エネルギを低減させた材料を用いれ
ば良いことが判明した。特に結晶構造を変化させるには
ドープ材料を変更すれば良いから次に材料の結晶構造の
選定について述べる。From the above-mentioned first and second points, it is sufficient to use a material having a reduced crystal structure and reduced ion activation energy based on a material resistant to reduction, ZrO 2 system or CeO 2 system. There was found. Particularly, in order to change the crystal structure, it is sufficient to change the doping material, so that selection of the crystal structure of the material will be described below.

【００１７】ペロブスカイト型構造とは、立方晶系に所
属し、ＡＢＯ3の化学式で表現される。その構造図を図
４に示す。酸素イオン導電性の例は、ＣａＺｒＯ3，Ｓ
ｒＺｒＯ3，ＢａＺｒＯ2，ＣａＣｅＯ3，ＳｒＣｅＯ3，
ＢａＣｅＯ3などである。多くは、やや歪んだ構造をと
る。The perovskite structure belongs to the cubic system and is represented by the chemical formula of ABO 3 . FIG. 4 shows the structure diagram. Examples of oxygen ion conductivity are CaZrO 3 , S
rZrO 3 , BaZrO 2 , CaCeO 3 , SrCeO 3 ,
BaCeO 3 and the like. Many have a slightly distorted structure.

【００１８】次に、蛍石型構造について述べる。蛍石型
も立方晶系に所属し、化学式はＡＯ2である。構造図は
図５である。Ａは＋４価のイオンで、酸素イオン導電性
を持たすために２価や３価の陽イオン（Ｍｇ2+，Ｃａ2
+．Ｂａ2+，Ｓｒ2+，Ｙ3+，Ｇｄ3+，Ｎｄ3+，Ｓｃ3+，
Ｓｍ3+）で部分的に置換させることが多い。酸素イオン
導電性の例はＺｒＯ2，ＣｅＯ2である。Next, the fluorite type structure will be described. The fluorite type also belongs to the cubic system, and the chemical formula is AO 2 . FIG. 5 is a structural diagram. A is a +4 ion, which is a divalent or trivalent cation (Mg2 +, Ca2
+. Ba2 +, Sr2 +, Y3 +, Gd3 +, Nd3 +, Sc3 +,
(Sm3 +). Examples of oxygen ion conductivity are ZrO 2 and CeO 2 .

【００１９】次は、酸素イオン空孔の生じる理由を述べ
る。酸素イオン空孔の濃度はドープ材に依存する。例え
ば、ＣｅＯ2系電解質においては、３価の希土類酸化物
Ｓｍ2Ｏ3を適量ドープするとＣｅ4+イオンがＳｍ3+イオ
ンに置換されるが、この時に電荷を補償するために、Ｓ
ｍ3+イオンが２つで１個の酸素イオン空孔が生じる。た
だし、ドープ材を加え過ぎるとＳｍ3+イオン同士の会合
が生じて結晶構造が崩れてしまう。Next, the reason why oxygen ion vacancies are generated will be described. The concentration of oxygen ion vacancies depends on the dopant. For example, in a CeO 2 -based electrolyte, when a trivalent rare earth oxide Sm 2 O 3 is appropriately doped, Ce 4+ ions are replaced with Sm 3+ ions.
One oxygen ion vacancy is generated by two m 3+ ions. However, if the doping material is added too much, Sm 3+ ions will associate with each other and the crystal structure will be broken.

【００２０】さて、ＢａＣｅ0・8Ｙ0・2Ｏ3-Xは、安定な
酸素欠損型ペロブスカイトの結晶構造を持つ酸化物で、
活性化エネルギは０.３ｅＶであることが知られてい
る。この構造はペロブスカイト型構造に＋３価のイオン
をドープするか、蛍石構造に＋２価イオンをドープする
かの両方の方法で作成できる。BaCe 0.8 Y 0 2 O 3-X is an oxide having a stable oxygen-deficient perovskite crystal structure.
The activation energy is known to be 0.3 eV. This structure can be prepared by both doping the perovskite structure with +3 valence ions and the fluorite structure with +2 valence ions.

【００２１】上記のことから蛍石型構造とペロブスカイ
ト型構造の中間に存在する安定な欠損型ペロブスカイト
構造をセリアなど還元に強い材料と組み合わせた種類を
次の表１に示す。材料の組み合わせは、表１に示すＡ，
Ｂ，Ｃの３種類で、Ａは主たる材料、Ｂは＋２価の材
料、Ｃは＋３価の材料である。Based on the above, the following Table 1 shows the types in which the stable defective perovskite structure existing between the fluorite structure and the perovskite structure is combined with a material resistant to reduction such as ceria. The combinations of the materials are shown in Table 1, A,
There are three types, B and C, where A is a main material, B is a +2 valent material, and C is a +3 valent material.

【００２２】[0022]

【表１】 [Table 1]

【００２３】保護膜の実施例１として、上記表１の材料
Ａ，Ｂ，Ｃの粉体をモル比０.８：１：０.１で混合し、
仮焼後、ペレット（保護膜）を１トン／ｃｍ2の圧力で
プレス成型して１３００℃１０時間で焼成し、作製し
た。ペレットは直径φ２５ｍｍで研磨により１ｍｍまで
厚みを薄くした。直径φ２５ｍｍ、厚さ１ｍｍの固体電
解質（Ｓｍ2Ｏ3入りＣｅＯ2）ペレットを用意し、前述
のようにして作製したペレット（保護膜）と張り合わせ
て、固体電解質をカソード側にして回路開放時のアノー
ドとカソード間の電圧を測定した。なお、カソードに酸
素ガス、アノードには水素ガス（水蒸気３％）を供給
し、温度は６００℃である。電極はアノード、カソード
に多孔質の白金を使用し、電極面積は０．７８５ｃｍ2
（φ：１０ｍｍ）で測定した。As Example 1 of the protective film, powders of the materials A, B and C shown in Table 1 were mixed at a molar ratio of 0.8: 1: 0.1.
After calcination, the pellet (protective film) was press-molded under a pressure of 1 ton / cm 2 and baked at 1300 ° C. for 10 hours to produce. The pellets were 25 mm in diameter and the thickness was reduced to 1 mm by polishing. A solid electrolyte (CeO 2 containing Sm 2 O 3 ) pellet having a diameter of φ25 mm and a thickness of 1 mm was prepared and bonded to the pellet (protective film) prepared as described above, and the solid electrolyte was placed on the cathode side when the circuit was opened. The voltage between the anode and cathode was measured. Note that oxygen gas is supplied to the cathode, and hydrogen gas (water vapor 3%) is supplied to the anode, and the temperature is 600 ° C. The electrode uses porous platinum for the anode and the cathode, and the electrode area is 0.785 cm 2.
(Φ: 10 mm).

【００２４】次に固体電解質と化学的に接合した酸素欠
損型ペロブスカイト結晶構造の保護膜の作製方法を実施
例２として述べる。直径φ２０ｍｍの固体電解質基板上
にＢａＣＯ3の粉体を塗布して１０００℃で、５時間の
熱処理を行った。Ｂａが固体電解質内部に拡散し、固体
電解質の表面近傍に、欠損型ペロブスカイトのＢａXＣ
ｅ1-X-YＳｍYＯZができていることを電子顕微鏡観察と
ＸＲＤによる同定で確認した。特性の条件などは実施例
１の場合と同じである。Next, a method for producing a protective film having an oxygen-deficient perovskite crystal structure chemically bonded to a solid electrolyte will be described as a second embodiment. BaCO 3 powder was applied on a solid electrolyte substrate having a diameter of φ20 mm and heat-treated at 1000 ° C. for 5 hours. Ba diffuses into the solid electrolyte, and near the surface of the solid electrolyte, Ba X C of a defective perovskite is formed.
The formation of e 1-XY Sm Y O Z was confirmed by observation with an electron microscope and identification by XRD. The conditions of the characteristics and the like are the same as in the first embodiment.

【００２５】前記表１中の材料番号Ａ２（ＣｅＯ2），
Ｂ４（ＢａＣＯ3），Ｃ５（Ｓｍ2Ｏ3）の配合に関して
はＮｉＯ（重量比４０％）をドープした混合物を実施例
３として直径φ２５ｍｍで、厚さ１ｍｍの固体電解質基
板上に塗布し、１３００℃で１０時間焼成した。ＮｉＯ
は水素雰囲気中で還元されてＮｉとなり、水素に対する
触媒となって電極となる。Material number A2 (CeO 2 ),
With respect to the blending of B4 (BaCO 3 ) and C5 (Sm 2 O 3 ), a mixture doped with NiO (40% by weight) was applied as Example 3 on a solid electrolyte substrate having a diameter of 25 mm and a thickness of 1 mm. It was baked at 10 ° C for 10 hours. NiO
Is reduced in a hydrogen atmosphere to become Ni, which serves as a catalyst for hydrogen and becomes an electrode.

【００２６】表２は実施例１の測定結果で、表２の番号
の読み方は、例えば、「１３４」はＺｒＯ2（表１に示
す材料Ａの１番）と、ＳｒＯ（同様に材料Ｂの３番）
と、Ｓｃ2Ｏ3（同様に材料Ｃの４番）を組み合わせてあ
るという意味である。Table 2 shows the measurement results of Example 1. The reading of the numbers in Table 2 is, for example, "134" means ZrO 2 (No. 1 of material A shown in Table 1) and SrO (Similarly, material B No. 3)
And Sc 2 O 3 (similarly, material C No. 4).

【００２７】[0027]

【表２】 [Table 2]

【００２８】[0028]

【発明の効果】以上述べたように、この発明によれば、
固体電解質のアノード側に緻密で、かつイオンと電子に
対して導電性のある保護膜を設けて固体電解質が割れて
もガス漏れを防止することができ、固体電解質型燃料電
池の実用化が容易にできるようになる利点がある。As described above, according to the present invention,
By providing a dense protective film on the anode side of the solid electrolyte and conductive to ions and electrons, gas leakage can be prevented even if the solid electrolyte cracks, making it easy to put a solid electrolyte fuel cell into practical use There are advantages to be able to.

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

【図１】この発明の実施の形態を示す概略的な構成説明
図。FIG. 1 is a schematic structural explanatory view showing an embodiment of the present invention.

【図２】固体電解質にひび割れが発生した状態を示す構
成説明図。FIG. 2 is a configuration explanatory view showing a state in which cracks have occurred in the solid electrolyte.

【図３】ＹＢａ2Ｃｕ3Ｏ7の結晶構造図。FIG. 3 is a crystal structure diagram of YBa 2 Cu 3 O 7 .

【図４】ペロブスカイト型構造図。FIG. 4 is a diagram showing a perovskite structure.

【図５】蛍石型構造図。FIG. 5 is a fluorite type structural diagram.

【図６】従来例のＳＯＦＣの概略構成図。FIG. 6 is a schematic configuration diagram of a conventional SOFC.

【図７】固体電解質にひび割れが発生した状態を示す構
成説明図。FIG. 7 is a configuration explanatory view showing a state in which cracks have occurred in the solid electrolyte.

【符号の説明】[Explanation of symbols]

１０…セル １１…多孔質の金属基板 １２…混合導電性の薄い保護膜 １３…固体電解質 １４…カソード極 １５…ひび割れ DESCRIPTION OF SYMBOLS 10 ... Cell 11 ... Porous metal substrate 12 ... Mixed protective thin protective film 13 ... Solid electrolyte 14 ... Cathode electrode 15 ... Crack

───────────────────────────────────────────────────── フロントページの続き (72)発明者 野口 孝卓 東京都品川区大崎２丁目１番17号 株式会 社明電舎内 (72)発明者 今澤 智恵子 東京都品川区大崎２丁目１番17号 株式会 社明電舎内 ──────────────────────────────────────────────────続 き Continued from the front page (72) Takataka Noguchi, Inventor 2-1-1, Osaki, Shinagawa-ku, Tokyo Inside the Meidensha Co., Ltd. (72) Chieko Imazawa 2-1-1, Osaki, Shinagawa-ku, Tokyo Stock Inside the company Meidensha

Claims (8)

【特許請求の範囲】[Claims] 【請求項１】 固体電解質に水素極と酸素極を形成し、
水素ガス若しくは天然ガスなどの燃料ガスを水素極側
に、酸素ガス若しくは空気を酸素極側に流して両極間に
電力を発生させる固体電解質型燃料電池において、 前記固体電解質の水素極側に、イオンと電子に対して導
電性のある混合導電性の保護膜を形成したことを特徴と
する固体電解質型燃料電池。Claims: 1. A hydrogen electrode and an oxygen electrode are formed on a solid electrolyte,
In a solid oxide fuel cell in which a fuel gas such as hydrogen gas or natural gas flows to the hydrogen electrode side, and oxygen gas or air flows to the oxygen electrode side to generate electric power between the two electrodes, And a mixed conductive protective film having conductivity with respect to electrons and electrons. 【請求項２】 前記保護膜は緻密な膜からなることを特
徴とする請求項１記載の固体電解質型燃料電池。2. The solid oxide fuel cell according to claim 1, wherein said protective film is formed of a dense film. 【請求項３】 前記固体電解質はＣｅＯ2を主たる成分
とする酸化物で構成したことを特徴とする請求項１記載
の固体電解質型燃料電池。3. The solid oxide fuel cell according to claim 1, wherein said solid electrolyte is composed of an oxide containing CeO 2 as a main component. 【請求項４】 前記保護膜はＮｉなどの水素に対して触
媒作用のある物質を混入することを特徴とする請求項１
または２記載の固体電解質型燃料電池。4. The protection film according to claim 1, wherein a substance having a catalytic action on hydrogen such as Ni is mixed in the protection film.
Or a solid oxide fuel cell according to 2. 【請求項５】 前記保護膜は、酸素イオン導電性のある
ペロブスカイトに＋３価の希土類元素を含む酸化物をド
ープして作製した酸素欠損型のペロブスカイト型結晶構
造の酸化物からなることを特徴とする請求項１記載の固
体電解質型燃料電池。5. The protective film according to claim 1, wherein the protective film is made of an oxide having an oxygen-deficient perovskite crystal structure formed by doping a perovskite having oxygen ion conductivity with an oxide containing a trivalent rare earth element. The solid oxide fuel cell according to claim 1. 【請求項６】 前記希土類元素を含む酸化物は、Ｙ
2Ｏ3，Ｇｄ2Ｏ3，Ｎｄ2Ｏ3，Ｓｃ2Ｏ3，Ｓｍ2Ｏ3を含む
ことを特徴とする請求項５記載の固体電解質型燃料電
池。6. The oxide containing a rare earth element is Y
6. The solid oxide fuel cell according to claim 5, comprising 2 O 3 , Gd 2 O 3 , Nd 2 O 3 , Sc 2 O 3 , and Sm 2 O 3 . 【請求項７】 前記ペロブスカイト型結晶構造の酸化物
は、Ｂａ，Ｓｒ，Ｃａ，Ｍｇを含むことを特徴とする請
求項５記載の固体電解質型燃料電池。7. The solid oxide fuel cell according to claim 5, wherein the oxide having a perovskite crystal structure contains Ba, Sr, Ca, and Mg. 【請求項８】 前記酸素欠損型のペロブスカイト型結晶
構造の酸化物は、ＣｅＯ2，ＺｒＯ2のモル比を０.８前
後に、ＢａＯ，ＳｒＯ，ＣａＯ，ＭｇＯのモル比を１前
後に、Ｙ2Ｏ3，Ｇｄ2Ｏ3，Ｎｄ2Ｏ3，Ｓｃ2Ｏ3，Ｓｍ2
Ｏ3のモル比を０.１前後に設定したことを特徴とする請
求項５記載の固体電解質型燃料電池。8. The oxide having an oxygen-deficient perovskite crystal structure has a molar ratio of CeO 2 and ZrO 2 of about 0.8, a molar ratio of BaO, SrO, CaO, and MgO of about 1, and Y has a molar ratio of about 1. 2 O 3 , Gd 2 O 3 , Nd 2 O 3 , Sc 2 O 3 , Sm 2
6. The solid oxide fuel cell according to claim 5, wherein the molar ratio of O 3 is set to about 0.1.
JP9322562A 1997-11-25 1997-11-25 Solid electrolyte fuel cell Pending JPH11162483A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9322562A JPH11162483A (en) 1997-11-25 1997-11-25 Solid electrolyte fuel cell

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9322562A JPH11162483A (en) 1997-11-25 1997-11-25 Solid electrolyte fuel cell

Publications (1)

Publication Number Publication Date
JPH11162483A true JPH11162483A (en) 1999-06-18

Family

ID=18145073

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9322562A Pending JPH11162483A (en) 1997-11-25 1997-11-25 Solid electrolyte fuel cell

Country Status (1)

Country Link
JP (1) JPH11162483A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001283876A (en) * 2000-04-03 2001-10-12 Tokyo Gas Co Ltd Unit cell of solid electrolytic fuel battery
JP2001283877A (en) * 2000-04-03 2001-10-12 Tokyo Gas Co Ltd Unit cell for solid electrolytic fuel battery and its manufacturing method
KR101051706B1 (en) * 2009-04-02 2011-07-25 더 보드 오브 트러스티스 오브 더 리랜드 스탠포드 주니어 유니버시티 Solid fuel cell comprising chemical electrolyte protective layer and manufacturing method thereof
WO2018212344A1 (en) * 2017-05-18 2018-11-22 国立研究開発法人産業技術総合研究所 Multilayer structure of electrode and mixed ion/electron conductive electrolyte and method for producing same

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001283876A (en) * 2000-04-03 2001-10-12 Tokyo Gas Co Ltd Unit cell of solid electrolytic fuel battery
JP2001283877A (en) * 2000-04-03 2001-10-12 Tokyo Gas Co Ltd Unit cell for solid electrolytic fuel battery and its manufacturing method
KR101051706B1 (en) * 2009-04-02 2011-07-25 더 보드 오브 트러스티스 오브 더 리랜드 스탠포드 주니어 유니버시티 Solid fuel cell comprising chemical electrolyte protective layer and manufacturing method thereof
US8669015B2 (en) 2009-04-02 2014-03-11 Samsung Electronics Co., Ltd. Solid-state fuel cell including anode and cathode chemical electrolyte protection layers and a hydrogen ion conductive solid oxide dense film
WO2018212344A1 (en) * 2017-05-18 2018-11-22 国立研究開発法人産業技術総合研究所 Multilayer structure of electrode and mixed ion/electron conductive electrolyte and method for producing same
JPWO2018212344A1 (en) * 2017-05-18 2020-03-26 国立研究開発法人産業技術総合研究所 Laminated structure of mixed ion / electron conductive electrolyte and electrode, and method of manufacturing the same

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