JP2006040822A - Porous mixed conductor, its manufacturing method, and air pole material of solid oxide fuel cell - Google Patents

Porous mixed conductor, its manufacturing method, and air pole material of solid oxide fuel cell Download PDF

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JP2006040822A
JP2006040822A JP2004222580A JP2004222580A JP2006040822A JP 2006040822 A JP2006040822 A JP 2006040822A JP 2004222580 A JP2004222580 A JP 2004222580A JP 2004222580 A JP2004222580 A JP 2004222580A JP 2006040822 A JP2006040822 A JP 2006040822A
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Kenji Yasumoto
憲司 安本
Hibiki Ito
響 伊藤
Toru Yamamoto
融 山本
Tetsuhisa Kobayashi
哲久 小林
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Central Research Institute of Electric Power Industry
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Abstract

<P>PROBLEM TO BE SOLVED: To prevent performance deterioration with time of air electrode materials of a solid oxide fuel cell. <P>SOLUTION: By making yttria stabilized zirconia as oxygen ion conductive materials, these oxygen ion conductive materials are divided into two groups, calcination-treatment is applied to one divided group which is made to be calcined materials 6, and the other non-calcined group is made to be non-calcined materials 7, and by making (La<SB>1-x</SB>Sr<SB>x</SB>)<SB>1-y</SB>MnO<SB>3</SB>(0≤x≤0.7, -0.05≤y≤0.1) as the base material 8, the calcined materials 6, the base material 8, and the non-calcined materials 7 are made to be powdered materials, particle diameters of the calcined materials 6 are made to be in the range of 1 μm to 20 μm, and the particle diameters of the non-calcined materials 7 and the base material 8 are made to be 1 μm or less, and on a condition that mass mixture ratio of the calcined materials 6, the base material 8, and the uncalcined materials 7 becomes 4:6:1, the calcined materials 6, the base material 8, and the uncalcined materials 7 are mixed, and are formed as a porous material 5 which has both the oxygen ion conductivity and the electric conductivity together. This porous mixted conductor 5 is made to be the air electrode of the solid oxide fuel cell. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、多孔質混合伝導体に関する。さらに詳述すると、本発明は、固体酸化物形燃料電池の空気極材料に用いられ酸素イオン伝導性と電子伝導性を併せ持つ多孔質の混合伝導体に関する。   The present invention relates to a porous mixed conductor. More specifically, the present invention relates to a porous mixed conductor that is used as an air electrode material of a solid oxide fuel cell and has both oxygen ion conductivity and electronic conductivity.

固体酸化物形燃料電池（Solid Oxide Fuel Cell、以下ＳＯＦＣとも呼ぶ。）は、図８に示すように、電解質１としてイットリア安定化ジルコニア（ＹＳＺ）などの酸素イオン伝導性（酸化物イオン伝導性とも呼ばれる）の固体電解質を用いており、この固体電解質１の両面に多孔質の空気極２と燃料極３が設けられている。尚、図８中の符号４は、供給される燃料ガスと空気を混合しないよう分離する隔壁としての機能と、隣接するセル同士を電気的に接続する集電板としての機能を兼ねたインターコネクタを示す。ＳＯＦＣの作動温度は、９００℃〜１０００℃と非常に高温であるため、構成材料は全て固体のセラミックス材料である。   As shown in FIG. 8, a solid oxide fuel cell (hereinafter also referred to as SOFC) has an oxygen ion conductivity (also referred to as oxide ion conductivity) such as yttria stabilized zirconia (YSZ) as an electrolyte 1. The solid electrolyte 1 is provided with a porous air electrode 2 and a fuel electrode 3 on both surfaces of the solid electrolyte 1. Reference numeral 4 in FIG. 8 denotes an interconnector that functions as a partition that separates the supplied fuel gas and air so as not to mix and functions as a current collector that electrically connects adjacent cells. Indicates. Since the operating temperature of SOFC is as high as 900 ° C. to 1000 ° C., the constituent materials are all solid ceramic materials.

ＳＯＦＣの空気極２は、１０００℃程度の作動条件下で、以下の条件を満足する必要がある。即ち、（１）電子伝導性が高いこと、（２）酸素イオン生成の反応場になること（換言すれば、酸素の吸着能を有すること）、（３）焼結し難く多孔質が維持できること、（４）熱力学的に安定であること、（５）他の構成材料との化学反応性が小さいこと（換言すれば、両立性が大きいこと）、（６）電解質１と熱膨張率が同等あるいは近いこと、である。上記条件を満たす空気極材料として、ランタン・ストロンチウム・マンガナイト（Ｌａ，Ｓｒ）ＭｎＯ３（以下、ＬＳＭとも呼ぶ。）が最も一般的に使用されている（例えば非特許文献１参照）。 The SOFC air electrode 2 needs to satisfy the following conditions under an operating condition of about 1000 ° C. That is, (1) high electron conductivity, (2) a reaction field for oxygen ion generation (in other words, oxygen adsorption ability), and (3) a porous structure that is difficult to sinter. (4) thermodynamically stable; (5) low chemical reactivity with other constituent materials (in other words, high compatibility); (6) electrolyte 1 and coefficient of thermal expansion. Equal or close. As an air electrode material that satisfies the above conditions, lanthanum, strontium, manganite (La, Sr) MnO 3 (hereinafter also referred to as LSM) is most commonly used (see, for example, Non-Patent Document 1).

空気極材料の電極性能は、気相／空気極／電解質の三相界面の電極反応場に左右される。空気極２を多孔質体とし、空気極２と電解質１の接触場を増加することで、電極反応場が増加し、この結果、電流密度が大きくなり、電極性能が高くなる。   The electrode performance of the air electrode material depends on the electrode reaction field at the gas phase / air electrode / electrolyte three-phase interface. By making the air electrode 2 a porous body and increasing the contact field between the air electrode 2 and the electrolyte 1, the electrode reaction field is increased, resulting in an increase in current density and an increase in electrode performance.

一方、ＳＯＦＣの燃料極材料として、特許文献１，２に開示されるように、酸化ニッケル（但し燃料電池作動時には金属ニッケルに変化する）とイットリア安定化ジルコニア（ＹＳＺ）との混合物（サーメット）が使用されている。例えば特許文献１の技術では、仮焼した粗ＹＳＺ粉末：ＮｉＯ粒子粉末：未焼成の微ＹＳＺ粉末の重量混合比を４：６：１とし、この重量混合比の下で粗ＹＳＺ粉末、ＮｉＯ粒子粉末、微ＹＳＺ粉末の各粉末粒子の粒径をそれぞれ２７．０μｍ、１．０μｍ、０．４μｍとしている。   On the other hand, as a fuel electrode material of SOFC, as disclosed in Patent Documents 1 and 2, a mixture (cermet) of nickel oxide (which changes to metallic nickel when the fuel cell is operated) and yttria stabilized zirconia (YSZ) is used. in use. For example, in the technique of Patent Document 1, the weight mixing ratio of calcined coarse YSZ powder: NiO particle powder: unfired fine YSZ powder is 4: 6: 1, and under this weight mixing ratio, the crude YSZ powder and NiO particles are mixed. The particle size of each powder particle of the powder and fine YSZ powder is 27.0 μm, 1.0 μm, and 0.4 μm, respectively.

他方、ＬＳＭとＹＳＺの混合物（サーメット）を空気極材料として、空気極性能を向上させた報告例がある（非特許文献２参照）。非特許文献２には、ＬＳＭ：ＹＳＺを４０質量％：６０質量％で混合すると、ＬＳＭとＹＳＺが接する三相界面が最も長くなるため反応場が多くなり、分極抵抗が小さくなり、抵抗が最小の値をとる旨が報告されている。尚、非特許文献２では使用されたＹＳＺは市販のものと記載されているため、その粒子径は１μｍ以下と推定される。   On the other hand, there is a report example in which air electrode performance is improved by using a mixture (cermet) of LSM and YSZ as an air electrode material (see Non-Patent Document 2). In Non-Patent Document 2, when LSM: YSZ is mixed at 40 mass%: 60 mass%, the three-phase interface where LSM and YSZ are in contact with each other is the longest, so the reaction field increases, the polarization resistance decreases, and the resistance is minimized. It has been reported to take the value of. In Non-Patent Document 2, since YSZ used is described as commercially available, the particle diameter is estimated to be 1 μm or less.

S. P. Jiang and J. G. Love, Solid State Ionics, 158, 45-53 (2003)S. P. Jiang and J. G. Love, Solid State Ionics, 158, 45-53 (2003) Jae-Dong Kim et al., Solid State Ionics, 143 (2001) 379-389Jae-Dong Kim et al., Solid State Ionics, 143 (2001) 379-389 特開２００４−７１３６０号JP 2004-71360 A 特開平８−３０６３６１号JP-A-8-306361

しかしながら、ＬＳＭ単体で構成される空気極２は、高温（１０００℃程度）下での長時間の大電流通電により、ＬＳＭ粒子が凝集してしまう問題がある（非特許文献１参考）。ＬＳＭ粒子が凝集することにより、気孔率が低下し、電極反応場が減少し、ガス拡散の阻害を生じ、空気極２全体の性能が低下してしまう。また、Ｎｉを用いた燃料極３に比べ、空気極２に由来する抵抗が大きいため、空気極２の抵抗は燃料電池の内部抵抗成分全体の半分以上を占めており、燃料電池の性能も大きく低下してしまう。   However, the air electrode 2 composed of LSM alone has a problem that LSM particles aggregate due to a long-time large current application at a high temperature (about 1000 ° C.) (see Non-Patent Document 1). Aggregation of the LSM particles reduces the porosity, reduces the electrode reaction field, inhibits gas diffusion, and degrades the performance of the entire air electrode 2. Further, since the resistance derived from the air electrode 2 is larger than that of the fuel electrode 3 using Ni, the resistance of the air electrode 2 accounts for more than half of the entire internal resistance component of the fuel cell, and the performance of the fuel cell is also large. It will decline.

また、非特許文献２の従来技術は、空気極２の性能の向上のみを目的としており、１０００℃程度の高温条件下での長時間作動時の空気極２の劣化についての検討がなされていない。従って、上述したＬＳＭ粒子の凝集および当該凝集に起因する問題が解決されておらず、燃料電池の運転時間の経過に伴って空気極２の性能が低下してしまう。   Further, the prior art of Non-Patent Document 2 is intended only to improve the performance of the air electrode 2, and no study has been made on the deterioration of the air electrode 2 during long-time operation under a high temperature condition of about 1000 ° C. . Therefore, the above-described aggregation of LSM particles and the problems caused by the aggregation are not solved, and the performance of the air electrode 2 is deteriorated as the operation time of the fuel cell elapses.

作動時間の経過に伴う空気極２の性能劣化を防止するべく、換言すれば、空気極２の経時安定性を実現するべく、特許文献１，２に開示された燃料極３についての技術を、非特許文献２に開示されたＬＳＭとＹＳＺの混合物（サーメット）に適用することが考えられる。しかし、本願発明者が実験したところ、特許文献１，２に開示された条件を単にＬＳＭとＹＳＺの混合物に適用するだけでは、経時安定性を備える空気極２を得ることができず、空気極２に求められる電極性能すら充分に満足できなかった。   In order to prevent the performance deterioration of the air electrode 2 with the passage of operating time, in other words, in order to realize the temporal stability of the air electrode 2, the technology regarding the fuel electrode 3 disclosed in Patent Documents 1 and 2 is It is conceivable to apply to a mixture (cermet) of LSM and YSZ disclosed in Non-Patent Document 2. However, as a result of experiments by the inventors of the present application, it is not possible to obtain the air electrode 2 having stability over time by simply applying the conditions disclosed in Patent Documents 1 and 2 to a mixture of LSM and YSZ. Even the electrode performance required for 2 was not fully satisfied.

また、酸素イオン伝導性と電子伝導性を併せ持つ多孔質の混合伝導体は、固体酸化物形燃料電池の空気極材料のみならず、多孔質を維持しながら酸素イオン伝導性または電子伝導性を示す材料を必要とする他の装置の構成部材として利用される可能性があるが、その場合にも、高温条件下での長時間使用により、上述したように多孔質混合伝導体の構成粒子が凝集し、性能劣化をもたらす虞がある。   Moreover, the porous mixed conductor having both oxygen ion conductivity and electron conductivity exhibits not only the air electrode material of the solid oxide fuel cell but also oxygen ion conductivity or electron conductivity while maintaining the porosity. Although it may be used as a constituent member of other devices that require materials, the constituent particles of the porous mixed conductor aggregate as described above due to long-term use under high temperature conditions. However, there is a risk of performance degradation.

そこで本発明は、高温条件下で長時間作動させる場合も性能劣化を見せず、経時安定性を備える多孔質混合伝導体およびその製造方法および固体酸化物形燃料電池の空気極材料を提供することを目的とする。   Accordingly, the present invention provides a porous mixed conductor having no deterioration in performance even when operated for a long time under a high temperature condition, a method for producing the same, and a cathode material for a solid oxide fuel cell. With the goal.

かかる目的を達成するため、請求項１記載の酸素イオン伝導性と電子伝導性を併せ持つ多孔質混合伝導体は、酸素イオン伝導性を備える第１材料と電子伝導性を備える第２材料との一方を、２つの群に分け、当該分けた一方の群に対して焼成処理を施しこれを仮焼材料とし、他方の未焼成の群を未焼成材料とし、前記第１材料と前記第２材料のうち上記焼成と未焼成の区別のない材料を基材料として、前記仮焼材料および前記基材料および前記未焼成材料を粉体とし、前記仮焼材料の粒子径を１μｍ〜２０μｍの範囲とし、前記未焼成材料の粒子径は前記仮焼材料の粒子径よりも小さいものとし、前記仮焼材料の質量混合比が前記未焼成材料の質量混合比よりも大きく、前記仮焼材料と前記基材料と前記未焼成材料とからなる全体に対する前記基材料の体積混合率が４０％以上６０％以下の範囲となる条件で、前記仮焼材料および前記基材料および前記未焼成材料が混合されてなるものとしている。   In order to achieve this object, the porous mixed conductor having both oxygen ion conductivity and electron conductivity according to claim 1 is one of a first material having oxygen ion conductivity and a second material having electron conductivity. Are divided into two groups, one of the divided groups is subjected to a firing treatment to be a calcined material, the other unfired group is an unfired material, and the first material and the second material Of these, the material that does not distinguish between fired and unfired as a base material, the calcined material and the base material and the unfired material as powder, the particle size of the calcined material is in the range of 1 μm to 20 μm, The particle size of the unfired material is smaller than the particle size of the calcined material, and the mass mixing ratio of the calcined material is larger than the mass mixing ratio of the unfired material, and the calcined material and the base material The whole of the green material The calcined material, the base material, and the unfired material are mixed under the condition that the volume mixing ratio of the base material is in the range of 40% to 60%.

また、請求項１１記載の多孔質混合伝導体の製造方法は、酸素イオン伝導性を備える第１材料と電子伝導性を備える第２材料との一方を、２つの群に分け、当該分けた一方の群に対して焼成処理を施しこれを仮焼材料とし、他方の未焼成の群を未焼成材料とし、前記第１材料と前記第２材料のうち上記焼成と未焼成の区別のない材料を基材料として、前記仮焼材料および前記基材料および前記未焼成材料を粉体とし、前記仮焼材料の粒子径を１μｍ〜２０μｍの範囲とし、前記未焼成材料の粒子径は前記仮焼材料の粒子径よりも小さいものとし、前記仮焼材料の質量混合比は前記未焼成材料の質量混合比よりも大きく、前記仮焼材料と前記基材料と前記未焼成材料とからなる全体に対する前記基材料の体積混合率が４０％以上６０％以下の範囲となる条件で、前記仮焼材料および前記基材料および前記未焼成材料を混合して、酸素イオン伝導性と電子伝導性を併せ持つ多孔質混合伝導体を得るようにしている。   The method for producing a porous mixed conductor according to claim 11 divides one of the first material having oxygen ion conductivity and the second material having electron conductivity into two groups, and the divided one A group is subjected to a firing treatment to be a calcined material, the other unfired group is an unfired material, and a material that does not distinguish between the fired and unfired of the first material and the second material. As the base material, the calcined material, the base material, and the unfired material are powders, the particle size of the calcined material is in a range of 1 μm to 20 μm, and the particle size of the unfired material is that of the calcined material. The base material with respect to the whole composed of the calcined material, the base material, and the unfired material, wherein the mass mixing ratio of the calcined material is larger than the mass mixing ratio of the unfired material. The volume mixing ratio is in the range of 40% to 60% Under such conditions, the calcined material, the base material, and the unfired material are mixed to obtain a porous mixed conductor having both oxygen ion conductivity and electron conductivity.

したがって、仮焼材料粒子と未焼成材料粒子によって多孔質混合伝導体内に骨格構造が形成され、その内部にガス拡散路としての気孔、ならびに電流パスと電極反応場を決定する基材料粒子がそれぞれ連続的に分散配置したミクロ構造が形成される。仮焼材料粒子が難焼結性を示し、基材料粒子を主とする多孔質混合伝導体の構成粒子の凝集を防ぐ。これにより、高温且つ長時間の作動条件下でも、気孔率の低下、電極反応場の減少、ガス拡散の阻害を防ぎ、多孔質混合伝導体全体の性能劣化を防ぐ。   Therefore, a skeletal structure is formed in the porous mixed conductor by the calcined material particles and the unfired material particles, and the pores as gas diffusion paths, and the base material particles that determine the current path and the electrode reaction field are continuous in the inside. A microscopically distributed microstructure is formed. The calcined material particles exhibit poor sinterability and prevent aggregation of the constituent particles of the porous mixed conductor mainly composed of the base material particles. This prevents a decrease in porosity, a decrease in electrode reaction field, an inhibition of gas diffusion, and a deterioration in performance of the entire porous mixed conductor even under high temperature and long-time operating conditions.

また、請求項２記載の発明は、請求項１記載の多孔質混合伝導体において、前記仮焼材料と前記基材料と前記未焼成材料の質量混合比が、ｘ：（１０−ｘ）：１であるものとしている。この混合条件を満足するとき、多孔質混合伝導体は良好な経時安定性を示す。   The invention according to claim 2 is the porous mixed conductor according to claim 1, wherein a mass mixing ratio of the calcined material, the base material, and the unfired material is x: (10−x): 1. It is supposed to be. When this mixing condition is satisfied, the porous mixed conductor exhibits good temporal stability.

また、請求項３記載の発明は、請求項１または２記載の多孔質混合伝導体において、前記第１材料は、ジルコニウム系酸化物（ＺｒＯ２または（Ｚｒ１−ｘ，Ａｘ）Ｏ２）、セリウム系酸化物（ＣｅＯ２または（Ｃｅ１−ｘ，Ａｘ）Ｏ２）、ビスマス系酸化物（δ−Ｂｉ２Ｏ３またはδ−（Ｂｉ１−ｘ，Ａｘ）２Ｏ３）、ランタン系酸化物（Ｌａ２Ｏ３または（Ｌａ１−ｘ，Ａｘ）２Ｏ３）、ハフニウム系酸化物（ＨｆＯ２または（Ｈｆ１−ｘ，Ａｘ）Ｏ２）、２Ａ族・３Ａ族元素系ガリウム酸化物（（Ｌ）１−ｚＧａＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｇａ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系アルミ酸化物（（Ｌ）１−ｚＡｌＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ａｌ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系コバルト酸化物（（Ｌ）１−ｚＣｏＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｃｏ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系鉄酸化物（（Ｌ）１−ｚＦｅＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｆｅ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系ジルコニウム酸化物（（Ｌ）２（１−ｚ）Ｚｒ２Ｏ７または（Ｌ１−ｘ，Ｂｘ）２（１−ｚ）（Ｚｒ１−ｙ，Ｄｙ）２Ｏ７）、２Ａ族・３Ａ族元素系チタン酸化物（（Ｂ）１−ｚＴｉＯ３または（Ｂ１−ｘ，Ｌｘ）１−ｚ（Ｔｉ１−ｙ，Ｍｙ）Ｏ３）のいずれかであるものとしている。ここで、前記Ａは放射性元素を除く価数２＋の金属元素（即ち、Ｂｅ，Ｍｇ，Ｃａ，Ｓｒ，Ｂａのいずれか）、または放射性元素を除く価数３＋の金属元素（即ち、Ｓｃ，Ｙ，ランタノイド（放射性元素であるＰｍは除く）のいずれか）、または上記の価数２＋もしくは価数３＋の金属元素の一部が他の１もしくは複数の価数２＋もしくは価数３＋の金属元素で置換されたものである。前記Ｂは放射性元素を除くアルカリ土類金属元素（即ち、２Ａ族元素のＢｅ，Ｍｇ，Ｃａ，Ｓｒ，Ｂａのいずれか）、または上記のアルカリ土類金属元素の一部が他の１もしくは複数の上記アルカリ土類金属元素で置換されたものである。尚、本明細書では、Ｂｅ，Ｍｇもアルカリ土類金属元素に含むものとする。また、前記ＤはＰｔと放射性元素を除く第４周期、第５周期、第６周期の遷移金属元素（即ち、Ｓｃ，Ｔｉ，Ｖ，Ｃｒ，Ｍｎ，Ｆｅ，Ｃｏ，Ｎｉ，Ｃｕ，Ｙ，Ｚｒ，Ｎｂ，Ｍｏ，Ｒｕ，Ｒｈ，Ｐｄ，Ａｇ，ランタノイド，Ｈｆ，Ｔａ，Ｗ，Ｒｅ，Ｏｓ，Ｉｒ，Ａｕのいずれか）、またはアルカリ土類金属元素、または上記の遷移金属元素もしくはアルカリ土類金属元素の一部が１もしくは複数の上記の遷移金属元素に属する他の元素もしくは他のアルカリ土類金属元素で置換されたものである。また、前記Ｌは放射性元素を除く３Ａ族の遷移金属元素（即ち、ランタノイド，Ｓｃ，Ｙのいずれか）、または前記３Ａ族元素の一部が１もしくは複数の他の前記３Ａ族元素で置換されたものである。また、前記Ｍは１Ａ族およびＨｇおよび放射性元素を除く典型金属元素（即ち、Ｂｅ，Ｍｇ，Ｃａ，Ｓｒ，Ｂａ，Ｚｎ，Ｃｄ，Ａｌ，Ｇａ，Ｉｎ，Ｔｌ，Ｇｅ，Ｓｎ，Ｐｂ，Ｓｂ，Ｂｉのいずれか）、または前記典型金属元素の一部が１もしくは複数の他の前記典型金属元素で置換されたものである。また、０＜ｘ≦１、０＜ｙ＜１、−０．０５≦ｚ≦０．１である。上記に列挙した材料は、酸素イオン伝導性を有しており、特に、ジルコニウム系酸化物、セリウム系酸化物、２Ａ族・３Ａ族元素系ガリウム酸化物、２Ａ族・３Ａ族元素系コバルト酸化物は、１０００℃程度の高温条件下でも化学的に安定であると共に高い酸素イオン伝導性を示し、第１材料として最適である。また、請求項４記載の発明は、請求項１または２記載の多孔質混合伝導体において、前記第１材料は、イットリア安定化ジルコニアまたはスカンジア安定化ジルコニアまたはスカンジア安定化ジルコニアのスカンジウムの一部がセリウムで置換されたものとしている。これらの材料は、１０００℃程度の高温条件下でも化学的に安定であると共に高い酸素イオン伝導性を示し、第１材料として最適である。 The invention according to claim 3 is the porous mixed conductor according to claim 1 or 2, wherein the first material is a zirconium-based oxide (ZrO 2 or (Zr 1-x , A x ) O 2 ). Cerium-based oxide (CeO 2 or (Ce 1-x , A x ) O 2 ), bismuth-based oxide (δ-Bi 2 O 3 or δ- (Bi 1-x , A x ) 2 O 3 ), Lanthanum-based oxides (La 2 O 3 or (La 1-x , A x ) 2 O 3 ), hafnium-based oxides (HfO 2 or (Hf 1-x , A x ) O 2 ), 2A group, 3A group elemental gallium oxide ((L) 1-z GaO 3 , or (L 1-x, B x ) 1-z (Ga 1-y, D y) O 3), 2A group · 3A group elements-based aluminum oxide ((L) 1-z AlO 3 or (L 1-x, B x ) 1-z (Al 1- , D y) O 3), 2A Group · 3A group elements-based cobalt oxide ((L) 1-z CoO 3 or (L 1-x, B x ) 1-z (Co 1-y, D y) O 3 ) Group 2A / Group 3A element-based iron oxide ((L) 1-z FeO 3 or (L 1-x , B x ) 1-z (Fe 1-y , D y ) O 3 ), Group 2A · 3A group elements-based zirconium oxide ((L) 2 (1- z) Zr 2 O 7 or (L 1-x, B x ) 2 (1-z) (Zr 1-y, D y) 2 O 7 ) Group 2A / Group 3A element-based titanium oxide ((B) 1-z TiO 3 or (B 1-x , L x ) 1-z (Ti 1-y , M y ) O 3 ) It is supposed to be. Here, A is a metal element having a valence of 2+ excluding radioactive elements (that is, any of Be, Mg, Ca, Sr, Ba), or a metal element having a valence of 3+ excluding radioactive elements (that is, Sc, Y). , Lanthanoids (excluding Pm which is a radioactive element)), or a part of the metal element having the valence 2+ or valence 3+ is one or more other valence 2+ or valence 3+ metal elements Has been replaced. B is an alkaline earth metal element excluding radioactive elements (that is, any of the group 2A elements Be, Mg, Ca, Sr, Ba), or a part of the alkaline earth metal element is one or more of the other Of the above-mentioned alkaline earth metal element. In this specification, Be and Mg are also included in the alkaline earth metal element. The D is a transition metal element (ie, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr) in the fourth period, the fifth period, and the sixth period excluding Pt and radioactive elements. Nb, Mo, Ru, Rh, Pd, Ag, lanthanoid, Hf, Ta, W, Re, Os, Ir, Au), or an alkaline earth metal element, or the above transition metal element or alkaline earth A part of the metal element is substituted with one or more other elements belonging to the above transition metal elements or other alkaline earth metal elements. The L is a group 3A transition metal element excluding radioactive elements (that is, any of lanthanoid, Sc, and Y), or a part of the group 3A element is substituted with one or more other group 3A elements. It is a thing. The M is a typical metal element excluding Group 1A and Hg and radioactive elements (ie, Be, Mg, Ca, Sr, Ba, Zn, Cd, Al, Ga, In, Tl, Ge, Sn, Pb, Sb, Bi), or a part of the typical metal element is substituted with one or more other typical metal elements. Further, 0 <x ≦ 1, 0 <y <1, and −0.05 ≦ z ≦ 0.1. The materials listed above have oxygen ion conductivity, and in particular, zirconium-based oxides, cerium-based oxides, group 2A / group 3A element-based gallium oxides, group 2A / group 3A element-based cobalt oxides. Is chemically stable under high temperature conditions of about 1000 ° C. and exhibits high oxygen ion conductivity, and is optimal as a first material. According to a fourth aspect of the present invention, there is provided the porous mixed conductor according to the first or second aspect, wherein the first material is a part of scandium of yttria stabilized zirconia, scandia stabilized zirconia, or scandia stabilized zirconia. It has been replaced with cerium. These materials are chemically stable under high temperature conditions of about 1000 ° C. and exhibit high oxygen ion conductivity, and are optimal as the first material.

また、請求項５記載の発明は、請求項１から４のいずれか１つに記載の多孔質混合伝導体において、前記第２材料は、２Ａ族・３Ａ族元素系ペロブスカイト型酸化物（（Ｌ）１−ｙ（Ｇ）Ｏ３または（Ｌ１−ｘ，Ｅｘ）１−ｙ（Ｇ）Ｏ３）であり、前記Ｌは放射性元素を除く３Ａ族の遷移金属元素または前記３Ａ族元素の一部が１もしくは複数の他の前記３Ａ族元素で置換されたものであり、前記Ｅはアルカリ土類金属元素（２Ａ族元素）または当該アルカリ土類金属元素の一部が１もしくは複数の他のアルカリ土類金属元素で置換されたものであり、前記ＧはＰｔと放射性元素を除く第４周期、第５周期、第６周期の遷移金属元素または当該遷移金属元素の一部が１もしくは複数の上記の遷移金属元素に属する他の元素で置換されたものであり、０＜ｘ≦１、−０．０５≦ｙ≦０．１であるものとしている。また、請求項６記載の発明は、請求項１から４のいずれか１つに記載の多孔質混合伝導体において、前記第２材料は、ランタノイド・マンガナイト系ペロブスカイト型酸化物（Ｌｎ１−ｙＭｎＯ３または（Ｌｎ１−ｘ，Ｅｘ）１−ｙＭｎＯ３）であり、前記Ｌｎはランタノイドまたは当該ランタノイドの一部が他の１もしくは複数のランタノイドで置換されたものであり、前記Ｅはアルカリ土類金属元素または当該アルカリ土類金属元素の一部が他の１もしくは複数のアルカリ土類金属元素で置換されたものであり、０＜ｘ≦０．７、−０．０５≦ｙ≦０．１であるものとしている。また、請求項７記載の発明は、請求項１から４のいずれか１つに記載の多孔質混合伝導体において、前記第２材料は、（Ｌａ１−ｘＳｒｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘＣａｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘ（Ｓｒ１−ｚＣａｚ）ｘ）１−ｙＭｎＯ３（但し、０＜ｘ≦０．７、−０．０５≦ｙ≦０．１、０＜ｚ＜１）であるものとしている。これらの材料は、１０００℃程度の高温条件下でも化学的に安定であると共に高い電子伝導性を示し、第２材料として最適である。 The invention according to claim 5 is the porous mixed conductor according to any one of claims 1 to 4, wherein the second material is a group 2A / 3A group elemental perovskite oxide ((L ) 1-y (G) O 3 or (L 1-x , E x ) 1-y (G) O 3 ), wherein L is a group 3A transition metal element excluding radioactive elements or the group 3A element A part thereof is substituted with one or a plurality of other 3A group elements, and E is an alkaline earth metal element (group 2A element) or a part of the alkaline earth metal element is one or more other G is a transition metal element in the fourth period, the fifth period, and the sixth period excluding Pt and a radioactive element, or one or more of the transition metal elements are part of the transition metal element. Substituted with other elements belonging to the above transition metal elements Are those, 0 <x ≦ 1, is assumed to be -0.05 ≦ y ≦ 0.1. The invention according to claim 6 is the porous mixed conductor according to any one of claims 1 to 4, wherein the second material is a lanthanoid-manganite-based perovskite oxide (Ln 1-y MnO 3 or (Ln 1-x , E x ) 1-y MnO 3 ), wherein Ln is a lanthanoid or a part of the lanthanoid substituted with one or more other lanthanoids, and E is An alkaline earth metal element or a part of the alkaline earth metal element is substituted with one or more other alkaline earth metal elements, and 0 <x ≦ 0.7, −0.05 ≦ y ≦ It is assumed that it is 0.1. The invention of claim 7, wherein, in the porous mixed conductor according to any one of claims 1 4, wherein the second material, (La 1-x Sr x ) 1-y MnO 3 or (La 1-x Ca x) 1-y MnO 3 or (La 1-x (Sr 1 -z Ca z) x) 1-y MnO 3 ( where, 0 <x ≦ 0.7, -0.05 ≦ It is assumed that y ≦ 0.1 and 0 <z <1). These materials are chemically stable under high temperature conditions of about 1000 ° C. and exhibit high electron conductivity, and are optimal as the second material.

また、請求項８記載の発明は、請求項１記載の多孔質混合伝導体において、前記第１材料はイットリア安定化ジルコニアＺｒ０．９２Ｙ０．０８Ｏ２であり、前記第２材料はランタン・ストロンチウム・マンガナイトＬａ０．６Ｓｒ０．４ＭｎＯ３であり、前記仮焼材料と前記基材料と前記未焼成材料の質量混合比が４：６：１であるものとしている。この条件を満足するとき、多孔質混合伝導体は良好な経時安定性を示す。 The invention according to claim 8 is the porous mixed conductor according to claim 1, wherein the first material is yttria stabilized zirconia Zr 0.92 Y 0.08 O 2 , and the second material is lanthanum. Strontium manganite La 0.6 Sr 0.4 MnO 3 and the mass mixing ratio of the calcined material, the base material, and the unfired material is 4: 6: 1. When this condition is satisfied, the porous mixed conductor exhibits good temporal stability.

また、請求項９記載の発明は、請求項１から８のいずれか１つに記載の多孔質混合伝導体において、前記未焼成材料および前記基材料の粒子径は１μｍ以下であるものとしている。この粒度条件を満足するとき、多孔質混合伝導体は良好な経時安定性を示す。   The invention according to claim 9 is the porous mixed conductor according to any one of claims 1 to 8, wherein the particle size of the unfired material and the base material is 1 μm or less. When this particle size condition is satisfied, the porous mixed conductor exhibits good temporal stability.

また、請求項１０記載の発明は、請求項１から９のいずれか１つに記載の多孔質混合伝導体において、前記焼成処理は１２００℃〜１６００℃で行われるものとしている。この温度条件で焼成を行うことで仮焼材料粒子が高い難焼結性を示し、基材料粒子を主とする多孔質混合伝導体の構成粒子の凝集を良好に防ぐ。   According to a tenth aspect of the present invention, in the porous mixed conductor according to any one of the first to ninth aspects, the firing treatment is performed at 1200 ° C to 1600 ° C. By calcining under this temperature condition, the calcined material particles exhibit high sinterability, and the agglomeration of the constituent particles of the porous mixed conductor mainly composed of the base material particles is favorably prevented.

また、請求項１１記載の固体酸化物形燃料電池の空気極材料は、請求項１から１０のいずれか１つに記載の多孔質混合伝導体を用いるものである。これにより、高い経時安定性を備える空気極が得られる。   An air electrode material for a solid oxide fuel cell according to claim 11 uses the porous mixed conductor according to any one of claims 1 to 10. Thereby, an air electrode having high temporal stability can be obtained.

また、請求項１２記載の固体酸化物形燃料電池の空気極材料は、イットリア安定化ジルコニアまたはスカンジア安定化ジルコニアまたはスカンジア安定化ジルコニアのスカンジウムの一部がセリウムで置換されたものを酸素イオン伝導性材料として、この酸素イオン伝導性材料を２つの群に分け、当該分けた一方の群に対して１２００℃〜１６００℃で焼成処理を施しこれを仮焼材料とし、他方の未焼成の群を未焼成材料とし、（Ｌａ１−ｘＳｒｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘＣａｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘ（Ｓｒ１−ｚＣａｚ）ｘ）１−ｙＭｎＯ３（但し、０＜ｘ≦０．７、−０．０５≦ｙ≦０．１、０＜ｚ＜１）を基材料として、前記仮焼材料および前記基材料および前記未焼成材料を粉体とし、前記仮焼材料の粒子径を１μｍ〜２０μｍの範囲とし、前記未焼成材料および前記基材料の粒子径は１μｍ以下とし、前記仮焼材料と前記基材料と前記未焼成材料の質量混合比が４：６：１となる条件で、前記仮焼材料および前記基材料および前記未焼成材料が混合されて、酸素イオン伝導性と電子伝導性を併せ持つ多孔質体として形成されるようにしている。 The air electrode material for a solid oxide fuel cell according to claim 12 is obtained by replacing oxygen ion conductivity of yttria-stabilized zirconia, scandia-stabilized zirconia, or scandia-stabilized zirconia with a part of scandium replaced with cerium. As a material, this oxygen ion conductive material is divided into two groups, one of the divided groups is subjected to a baking treatment at 1200 ° C. to 1600 ° C., and this is used as a calcined material, and the other unfired group is set as an unfired group. and firing the material, (La 1-x Sr x ) 1-y MnO 3 or (La 1-x Ca x) 1-y MnO 3 or (La 1-x (Sr 1 -z Ca z) x) 1-y Using MnO 3 (where 0 <x ≦ 0.7, −0.05 ≦ y ≦ 0.1, 0 <z <1) as a base material, the calcined material, the base material, and the unfired material are powdered. Body and The particle size of the calcined material is in the range of 1 μm to 20 μm, the particle size of the unfired material and the base material is 1 μm or less, and the mass mixing ratio of the calcined material, the base material, and the unfired material is 4 In the condition of 6: 1, the calcined material, the base material, and the unfired material are mixed to form a porous body having both oxygen ion conductivity and electron conductivity.

したがって、仮焼材料粒子と未焼成材料粒子によって空気極内に骨格構造が形成され、その内部にガス拡散路としての気孔、ならびに電流パスと電極反応場を決定する基材料粒子がそれぞれ連続的に分散配置したミクロ構造が形成される。この多孔質混合伝導体によれば、１０００℃程度の作動条件下でＳＯＦＣの空気極に求められる以下の条件を満足する。即ち、（１）電子伝導性が高く、（２）酸素イオン生成の反応場を有し（換言すれば、酸素の吸着能を有し）、（３）焼結し難く多孔質が維持でき、（４）熱力学的に安定であり、（５）他の構成材料との化学反応性が小さく（換言すれば、両立性が大きく）、（６）電解質と熱膨張率が同程度である。しかも仮焼された細ＹＳＺが難焼結性を示し、ＬＳＭ粒子を主とする空気極構成粒子の凝集を防ぐ。これにより、１０００℃程度の高温且つ長時間の作動条件下でも、気孔率の低下、電極反応場の減少、ガス拡散の阻害を防ぎ、空気極全体の性能劣化を防ぐ。これにより、空気極の経時安定性が実現される。Ｎｉ等を用いた燃料極に比べ、空気極に由来する抵抗が大きいため、空気極の抵抗は燃料電池の内部抵抗成分全体の半分以上を占めているが、空気極の経時的な性能低下の問題を解決することで、ＳＯＦＣ全体の性能を向上させることができる。また、空気極が酸素イオン伝導性と電子伝導性との混合伝導性を備えることで、空気極としての性能がより向上する。   Therefore, a skeletal structure is formed in the air electrode by the calcined material particles and the unfired material particles, and the pores as the gas diffusion paths and the base material particles that determine the current path and the electrode reaction field are continuously formed therein. A distributed microstructure is formed. According to this porous mixed conductor, the following conditions required for the SOFC air electrode under the operating condition of about 1000 ° C. are satisfied. That is, (1) high electron conductivity, (2) a reaction field for oxygen ion generation (in other words, oxygen adsorption ability), (3) it is difficult to sinter and maintain a porous structure, (4) thermodynamically stable, (5) low chemical reactivity with other constituent materials (in other words, high compatibility), and (6) thermal expansion coefficient is comparable to the electrolyte. Moreover, the calcined fine YSZ exhibits poor sinterability and prevents agglomeration of air electrode constituent particles mainly composed of LSM particles. This prevents a decrease in porosity, a decrease in electrode reaction field, an inhibition of gas diffusion, and a deterioration in the performance of the entire air electrode even under high temperature and long-time operating conditions of about 1000 ° C. Thereby, the temporal stability of the air electrode is realized. Since the resistance derived from the air electrode is larger than that of the fuel electrode using Ni or the like, the resistance of the air electrode accounts for more than half of the total internal resistance component of the fuel cell. By solving the problem, the performance of the SOFC as a whole can be improved. Moreover, the performance as an air electrode improves more because an air electrode is provided with mixed conductivity of oxygen ion conductivity and electronic conductivity.

しかして請求項１記載の多孔質混合伝導体および請求項１１記載の多孔質混合伝導体の製造方法によれば、仮焼材料粒子と未焼成材料粒子によって多孔質混合伝導体内に骨格構造が形成され、その内部にガス拡散路としての気孔、ならびに電流パスと電極反応場を決定する基材料粒子がそれぞれ連続的に分散配置したミクロ構造が形成される。そして、仮焼材料粒子が難焼結性を示し、基材料粒子を主とする多孔質混合伝導体の構成粒子の凝集を防ぐ。これにより、高温且つ長時間の作動条件下でも、気孔率の低下、電極反応場の減少、ガス拡散の阻害を防ぎ、多孔質混合伝導体全体の性能劣化を防ぐ。   Thus, according to the porous mixed conductor according to claim 1 and the method for producing the porous mixed conductor according to claim 11, a skeletal structure is formed in the porous mixed conductor by the calcined material particles and the unfired material particles. As a result, a micro-structure is formed in which pores as gas diffusion paths and base material particles that determine current paths and electrode reaction fields are continuously dispersed. The calcined material particles exhibit poor sinterability and prevent aggregation of the constituent particles of the porous mixed conductor mainly composed of the base material particles. This prevents a decrease in porosity, a decrease in electrode reaction field, an inhibition of gas diffusion, and a deterioration in performance of the entire porous mixed conductor even under high temperature and long-time operating conditions.

さらに、請求項２記載の混合条件を満足するとき、多孔質混合伝導体は良好な経時安定性を示す。   Furthermore, when the mixing conditions described in claim 2 are satisfied, the porous mixed conductor exhibits good stability over time.

さらに、請求項３，４記載の多孔質混合伝導体に用いる材料は、酸素イオン伝導性を有し、特に、ジルコニウム系酸化物、セリウム系酸化物、２Ａ族・３Ａ族元素系ガリウム酸化物、２Ａ族・３Ａ族元素系コバルト酸化物は、１０００℃程度の高温条件下でも化学的に安定であると共に高い酸素イオン伝導性を示し、第１材料として最適である。さらに、請求項５，６，７記載の多孔質混合伝導体に用いる材料は、１０００℃程度の高温条件下でも化学的に安定であると共に高い電子伝導性を示し、第２材料として最適である。   Furthermore, the material used for the porous mixed conductor according to claims 3 and 4 has oxygen ion conductivity, in particular, a zirconium-based oxide, a cerium-based oxide, a group 2A / group 3A element-based gallium oxide, The group 2A / group 3A element-based cobalt oxide is chemically stable under high temperature conditions of about 1000 ° C. and exhibits high oxygen ion conductivity, and is optimal as the first material. Furthermore, the material used for the porous mixed conductor according to claims 5, 6 and 7 is optimal as the second material because it is chemically stable and exhibits high electron conductivity even under high temperature conditions of about 1000 ° C. .

さらに、請求項８記載の条件を満足するとき、多孔質混合伝導体は良好な経時安定性を示す。さらに、請求項９記載の粒度条件を満足するとき、多孔質混合伝導体は良好な経時安定性を示す。   Furthermore, when the condition of claim 8 is satisfied, the porous mixed conductor exhibits good temporal stability. Furthermore, when the particle size condition of claim 9 is satisfied, the porous mixed conductor exhibits good stability over time.

さらに、請求項１０記載の温度条件で焼成を行うことで仮焼材料粒子が高い難焼結性を示し、基材料粒子を主とする多孔質混合伝導体の構成粒子の凝集を良好に防ぐ。   Furthermore, by calcining under the temperature conditions described in claim 10, the calcined material particles exhibit high sinterability and satisfactorily prevent aggregation of the constituent particles of the porous mixed conductor mainly composed of the base material particles.

さらに、請求項１１記載の発明によれば、高い経時安定性を備える固体酸化物形燃料電池の空気極材料が得られる。   Furthermore, according to the eleventh aspect of the invention, an air electrode material for a solid oxide fuel cell having high temporal stability can be obtained.

さらに、請求項１２記載の発明によれば、仮焼材料粒子と未焼成材料粒子によって空気極内に骨格構造が形成され、その内部にガス拡散路としての気孔、ならびに電流パスと電極反応場を決定する基材料粒子がそれぞれ連続的に分散配置したミクロ構造が形成される。この多孔質混合伝導体によれば、１０００℃程度の作動条件下でＳＯＦＣの空気極に求められる以下の条件を満足する。即ち、（１）電子伝導性が高く、（２）酸素イオン生成の反応場を有し（換言すれば、酸素の吸着能を有し）、（３）焼結し難く多孔質が維持でき、（４）熱力学的に安定であり、（５）他の構成材料との化学反応性が小さく（換言すれば、両立性が大きく）、（６）電解質と熱膨張率が同程度である。しかも仮焼された細ＹＳＺが難焼結性を示し、ＬＳＭ粒子を主とする空気極構成粒子の凝集を防ぐ。これにより、１０００℃程度の高温且つ長時間の作動条件下でも、気孔率の低下、電極反応場の減少、ガス拡散の阻害を防ぎ、空気極全体の性能劣化を防ぐ。これにより、空気極の経時安定性が実現される。Ｎｉ等を用いた燃料極に比べ、空気極に由来する抵抗が大きいため、空気極の抵抗は燃料電池の内部抵抗成分全体の半分以上を占めているが、空気極の経時的な性能低下の問題を解決することで、ＳＯＦＣ全体の性能を向上させることができる。また、空気極が酸素イオン伝導性と電子伝導性との混合伝導性を備えることで、空気極としての性能がより向上する。   Furthermore, according to the twelfth aspect of the present invention, a skeletal structure is formed in the air electrode by the calcined material particles and the unfired material particles, and pores as gas diffusion paths, current paths, and electrode reaction fields are formed therein. A microstructure is formed in which the base material particles to be determined are continuously dispersed. According to this porous mixed conductor, the following conditions required for the SOFC air electrode under the operating condition of about 1000 ° C. are satisfied. That is, (1) high electron conductivity, (2) a reaction field for oxygen ion generation (in other words, oxygen adsorption ability), (3) it is difficult to sinter and maintain a porous structure, (4) thermodynamically stable, (5) low chemical reactivity with other constituent materials (in other words, high compatibility), and (6) thermal expansion coefficient is comparable to the electrolyte. Moreover, the calcined fine YSZ exhibits poor sinterability and prevents agglomeration of air electrode constituent particles mainly composed of LSM particles. This prevents a decrease in porosity, a decrease in electrode reaction field, an inhibition of gas diffusion, and a deterioration in the performance of the entire air electrode even under high temperature and long-time operating conditions of about 1000 ° C. Thereby, the temporal stability of the air electrode is realized. Since the resistance derived from the air electrode is larger than that of the fuel electrode using Ni or the like, the resistance of the air electrode accounts for more than half of the total internal resistance component of the fuel cell. By solving the problem, the performance of the SOFC as a whole can be improved. Moreover, the performance as an air electrode improves more because an air electrode is provided with mixed conductivity of oxygen ion conductivity and electronic conductivity.

以下、本発明の構成を図面に示す実施形態に基づいて詳細に説明する。   Hereinafter, the configuration of the present invention will be described in detail based on embodiments shown in the drawings.

図１から図８に本発明の多孔質混合伝導体の実施の一形態を示す。本実施形態では、本発明の多孔質混合伝導体５を固体酸化物形燃料電池（図８参照）の空気極材料として用いた例について説明する。酸素イオン伝導性と電子伝導性を併せ持つこの多孔質混合伝導体５は、酸素イオン伝導性を備える第１材料と電子伝導性を備える第２材料との一方を、２つの群に分け、当該分けた一方の群に対して焼成処理を施しこれを仮焼材料６とし、他方の未焼成の群を未焼成材料７とし、第１材料と第２材料のうち上記焼成と未焼成の区別のない材料を基材料８として、仮焼材料６および基材料８および未焼成材料７を粉体とし、仮焼材料６の粒子径を１μｍ〜２０μｍの範囲とし、未焼成材料７の粒子径は仮焼材料６の粒子径よりも小さいものとし、仮焼材料６の質量混合比が未焼成材料７の質量混合比よりも大きく、仮焼材料６と基材料８と未焼成材料７とからなる全体に対する基材料８の体積混合率が４０％以上６０％以下の範囲となる条件で、仮焼材料６および基材料８および未焼成材料７が混合されてなるものとしている。   1 to 8 show an embodiment of the porous mixed conductor of the present invention. In the present embodiment, an example in which the porous mixed conductor 5 of the present invention is used as an air electrode material of a solid oxide fuel cell (see FIG. 8) will be described. In this porous mixed conductor 5 having both oxygen ion conductivity and electron conductivity, one of the first material having oxygen ion conductivity and the second material having electron conductivity is divided into two groups. One of the groups is subjected to a firing treatment to be a calcined material 6, the other unfired group is an unfired material 7, and the first material and the second material are not distinguished from the fired and unfired materials. The material is the base material 8, the calcined material 6, the base material 8 and the unfired material 7 are powdered, the particle size of the calcined material 6 is in the range of 1 μm to 20 μm, and the particle size of the unfired material 7 is calcined It is assumed that the particle size of the material 6 is smaller, the mass mixing ratio of the calcined material 6 is larger than the mass mixing ratio of the unfired material 7, and the whole composed of the calcined material 6, the base material 8, and the unfired material 7. Under the condition that the volume mixing ratio of the base material 8 is in the range of 40% to 60%, The calcined material 6, the base material 8, and the unfired material 7 are mixed.

酸素イオン伝導性を備える第１材料としては、例えば、ジルコニウム系酸化物（ＺｒＯ２または（Ｚｒ１−ｘ，Ａｘ）Ｏ２）、セリウム系酸化物（ＣｅＯ２または（Ｃｅ１−ｘ，Ａｘ）Ｏ２）、ビスマス系酸化物（δ−Ｂｉ２Ｏ３またはδ−（Ｂｉ１−ｘ，Ａｘ）２Ｏ３）、ランタン系酸化物（Ｌａ２Ｏ３または（Ｌａ１−ｘ，Ａｘ）２Ｏ３）、ハフニウム系酸化物（ＨｆＯ２または（Ｈｆ１−ｘ，Ａｘ）Ｏ２）、２Ａ族・３Ａ族元素系ガリウム酸化物（（Ｌ）１−ｚＧａＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｇａ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系アルミ酸化物（（Ｌ）１−ｚＡｌＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ａｌ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系コバルト酸化物（（Ｌ）１−ｚＣｏＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｃｏ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系鉄酸化物（（Ｌ）１−ｚＦｅＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｆｅ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系ジルコニウム酸化物（（Ｌ）２（１−ｚ）Ｚｒ２Ｏ７または（Ｌ１−ｘ，Ｂｘ）２（１−ｚ）（Ｚｒ１−ｙ，Ｄｙ）２Ｏ７）、２Ａ族・３Ａ族元素系チタン酸化物（（Ｂ）１−ｚＴｉＯ３または（Ｂ１−ｘ，Ｌｘ）１−ｚ（Ｔｉ１−ｙ，Ｍｙ）Ｏ３）などが利用可能である。ここで、０＜ｘ＜１、０＜ｙ＜１、−０．０５≦ｚ≦０．１である。尚、ビスマス系酸化物のδは結晶構造を示し、このビスマス系酸化物は高温相を示す。ここで、上記組成式の中のＡは、放射性元素を除く価数２＋の金属元素（即ち、Ｂｅ，Ｍｇ，Ｃａ，Ｓｒ，Ｂａのいずれか）、または放射性元素を除く価数３＋の金属元素（即ち、Ｓｃ，Ｙ，ランタノイドのいずれか）、または上記の価数２＋もしくは価数３＋の金属元素の一部が他の１もしくは複数の価数２＋もしくは価数３＋の金属元素で置換されたものである。また、Ｂは、放射性元素を除くアルカリ土類金属元素（即ち、２Ａ族元素のＢｅ，Ｍｇ，Ｃａ，Ｓｒ，Ｂａのいずれか）である。尚、本明細書では、Ｂｅ，Ｍｇもアルカリ土類金属元素に含むものとする。また、Ｄは、Ｐｔと放射性元素を除く第４周期、第５周期、第６周期の遷移金属元素（即ち、Ｓｃ，Ｔｉ，Ｖ，Ｃｒ，Ｍｎ，Ｆｅ，Ｃｏ，Ｎｉ，Ｃｕ，Ｙ，Ｚｒ，Ｎｂ，Ｍｏ，Ｒｕ，Ｒｈ，Ｐｄ，Ａｇ，ランタノイド，Ｈｆ，Ｔａ，Ｗ，Ｒｅ，Ｏｓ，Ｉｒ，Ａｕのいずれか）、またはアルカリ土類金属元素、または上記の遷移金属元素もしくはアルカリ土類金属元素の一部が１もしくは複数の上記の遷移金属元素に属する他の元素もしくは他のアルカリ土類金属元素で置換されたものである。また、Ｌは、放射性元素を除く３Ａ族の遷移金属元素（即ち、ランタノイド，Ｓｃ，Ｙのいずれか）、または上記の３Ａ族元素の一部が１もしくは複数の他の上記の３Ａ族元素で置換されたものである。また、Ｍは１Ａ族およびＨｇおよび放射性元素を除く典型金属元素（即ち、Ｂｅ，Ｍｇ，Ｃａ，Ｓｒ，Ｂａ，Ｚｎ，Ｃｄ，Ａｌ，Ｇａ，Ｉｎ，Ｔｌ，Ｇｅ，Ｓｎ，Ｐｂ，Ｓｂ，Ｂｉのいずれか）、または上記の典型金属元素の一部が１もしくは複数の他の上記の典型金属元素で置換されたものである。例えば、（Ｌａ，Ｓｒ）（Ｇａ，Ｍｇ，Ｃｏ）Ｏ３は低温（６００〜８００℃）用のＳＯＦＣの電解質として従来用いられている。 Examples of the first material having oxygen ion conductivity include zirconium-based oxide (ZrO 2 or (Zr 1-x , A x ) O 2 ), cerium-based oxide (CeO 2 or (Ce 1-x , A x ) O 2 ), bismuth oxide (δ-Bi 2 O 3 or δ- (Bi 1-x , A x ) 2 O 3 ), lanthanum oxide (La 2 O 3 or (La 1-x , A x ) 2 O 3 ), hafnium-based oxide (HfO 2 or (Hf 1-x , A x ) O 2 ), group 2A / group 3A element-based gallium oxide ((L) 1-z GaO 3 or ( L 1-x , B x ) 1-z (Ga 1-y , D y ) O 3 ), group 2A / 3A group element-based aluminum oxide ((L) 1-z AlO 3 or (L 1-x , B x) 1-z (Al 1-y, D y) O 3), 2A group · 3A group elements-based Baltic oxide ((L) 1-z CoO 3 or (L 1-x, B x ) 1-z (Co 1-y, D y) O 3), 2A Group · 3A group elements-based iron oxide (( L) 1-z FeO 3 or (L 1-x , B x ) 1-z (Fe 1-y , D y ) O 3 ), group 2A / group 3A element-based zirconium oxide ((L) 2 (1 -Z) Zr 2 O 7 or (L 1-x , B x ) 2 (1-z) (Zr 1-y , D y ) 2 O 7 ), group 2A-3A group element titanium oxide ((B 1-z TiO 3 or (B 1-x , L x ) 1-z (Ti 1-y , M y ) O 3 ) or the like can be used. Here, 0 <x <1, 0 <y <1, and −0.05 ≦ z ≦ 0.1. Note that δ of the bismuth-based oxide indicates a crystal structure, and this bismuth-based oxide indicates a high-temperature phase. Here, A in the above composition formula is a metal element having a valence of 2+ excluding a radioactive element (that is, any of Be, Mg, Ca, Sr, Ba) or a metal element having a valence of 3+ excluding a radioactive element. (That is, any one of Sc, Y, and a lanthanoid), or a part of the valence 2+ or valence 3+ metal element is replaced with one or more other valence 2+ or valence 3+ metal elements Is. Further, B is an alkaline earth metal element excluding radioactive elements (that is, any one of the group 2A elements Be, Mg, Ca, Sr, and Ba). In this specification, Be and Mg are also included in the alkaline earth metal element. D is a transition metal element (ie, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr) in the fourth, fifth, and sixth periods excluding Pt and radioactive elements. Nb, Mo, Ru, Rh, Pd, Ag, lanthanoid, Hf, Ta, W, Re, Os, Ir, Au), or an alkaline earth metal element, or the above transition metal element or alkaline earth A part of the metal element is substituted with one or more other elements belonging to the above transition metal elements or other alkaline earth metal elements. In addition, L is a group 3A transition metal element excluding radioactive elements (that is, any one of the lanthanoid, Sc, and Y), or a part of the group 3A element is one or more other group 3A elements. Has been replaced. M is a typical metal element excluding Group 1A and Hg and radioactive elements (ie, Be, Mg, Ca, Sr, Ba, Zn, Cd, Al, Ga, In, Tl, Ge, Sn, Pb, Sb, Bi). Or a part of the above typical metal element is substituted with one or more of the above typical metal elements. For example, (La, Sr) (Ga, Mg, Co) O 3 is conventionally used as an SOFC electrolyte for low temperature (600 to 800 ° C.).

ここで、第１材料は酸素イオン伝導性を有するものであれば、電子伝導性を同時に有する材料であっても構わない。第１材料は、隣接する他の材料（例えば第２材料）と固相反応を起こさない材料であることが好ましく、特に、ジルコニウム系酸化物、セリウム系酸化物、２Ａ族・３Ａ族元素系ガリウム酸化物、２Ａ族・３Ａ族元素系コバルト酸化物は、１０００℃程度の高温条件下でも化学的に安定であると共に高い酸素イオン伝導性を示し、第１材料として最適である。例えば固体酸化物形燃料電池の固体電解質１として従来用いられている材料、例えばイットリア安定化ジルコニア（ＹＳＺ）やスカンジア安定化ジルコニア（ＳＳＺ）またはスカンジア安定化ジルコニアのスカンジウムの一部がセリウムで置換されたものの利用が好ましい。１０００℃で作動するＳＯＦＣにおいては、特に１０００℃の作動条件下で酸素イオン伝導性の高いＺｒ０．９２Ｙ０．０８Ｏ２（８ＹＳＺ）やＺｒ０．８９Ｓｃ０．１Ｃｅ０．０１Ｏ２（ＳＳＺ）が第１材料として最適である。例えば本実施形態では、８モル％のイットリアを固溶して結晶構造を安定化させたジルコニア（Ｚｒ０．９２Ｙ０．０８Ｏ２（８ＹＳＺ））を第１材料として用いる。 Here, as long as the first material has oxygen ion conductivity, it may be a material having electron conductivity at the same time. The first material is preferably a material that does not cause a solid phase reaction with another adjacent material (for example, the second material), and in particular, a zirconium-based oxide, a cerium-based oxide, a group 2A / group 3A element-based gallium. Oxides, group 2A / group 3A element-based cobalt oxides are chemically stable under high temperature conditions of about 1000 ° C., exhibit high oxygen ion conductivity, and are optimal as the first material. For example, a part of the scandium of a material conventionally used as the solid electrolyte 1 of the solid oxide fuel cell, for example, yttria stabilized zirconia (YSZ), scandia stabilized zirconia (SSZ), or scandia stabilized zirconia is substituted with cerium. It is preferable to use one. In an SOFC operating at 1000 ° C., Zr 0.92 Y 0.08 O 2 (8YSZ) or Zr 0.89 Sc 0.1 Ce 0.01 O, which has high oxygen ion conductivity, especially under operating conditions at 1000 ° C. 2 (SSZ) is optimal as the first material. For example, in this embodiment, zirconia (Zr 0.92 Y 0.08 O 2 (8YSZ)) in which 8 mol% of yttria is dissolved to stabilize the crystal structure is used as the first material.

電子伝導性を備える第２材料としては、例えば、２Ａ族・３Ａ族元素系ペロブスカイト型酸化物（（Ｌ）１−ｙ（Ｇ）Ｏ３または（Ｌ１−ｘ，Ｅｘ）１−ｙ（Ｇ）Ｏ３）などが利用可能である。ここで、上記組成式の中のＬは放射性元素を除く３Ａ族の遷移金属元素（即ち、ランタノイド，Ｓｃ，Ｙのいずれか）、または前記３Ａ族元素の一部が１もしくは複数の他の前記３Ａ族元素で置換されたものであり、Ｅはアルカリ土類金属元素（２Ａ族元素）または当該アルカリ土類金属元素の一部が他の１もしくは複数のアルカリ土類金属元素で置換されたものであり、ＧはＰｔと放射性元素を除く第４周期、第５周期、第６周期の遷移金属元素または当該遷移金属元素の一部が上記の遷移金属元素に属する他の１もしくは複数の元素で置換されたものである。ここで、（Ｌ＋Ｅ）のモル比は、Ｇを１として、０．９〜１．０５の範囲が好ましい。また、ＬとＥのモル比は、単一相が存在する全ての値をとり得る。特に、ＧがＣｒ，Ｍｎ，Ｆｅ，Ｃｏ，Ｎｉのいずれか５０ｍｏｌ％以上置換されたものは、Ｌのモル比が０．１〜０．７の時、ＳＯＦＣの空気極２として最適である。即ち、（ＬｘＥ１−ｘ）ｙ（Ｇ）Ｏ３（０．１≦ｘ≦０．７、０．９≦ｙ≦１．０５）が特に好ましい。 As the second material having electron conductivity, for example, a group 2A / group 3A element-based perovskite oxide ((L) 1-y (G) O 3 or (L 1-x , E x ) 1-y ( G) O 3 ) etc. can be used. Here, L in the composition formula is a 3A group transition metal element excluding a radioactive element (that is, any one of the lanthanoid, Sc, and Y), or a part of the 3A group element is one or a plurality of the other elements. It is substituted with a group 3A element, and E is an alkaline earth metal element (group 2A element) or a part of the alkaline earth metal element substituted with one or more other alkaline earth metal elements G is a transition metal element in the fourth period, the fifth period, and the sixth period, excluding Pt and a radioactive element, or one or a plurality of other elements in which a part of the transition metal element belongs to the above transition metal element. Has been replaced. Here, the molar ratio of (L + E) is preferably in the range of 0.9 to 1.05, where G is 1. Moreover, the molar ratio of L and E can take all values in which a single phase exists. In particular, G in which 50 mol% or more of Cr, Mn, Fe, Co, and Ni is substituted is optimal as the SOFC air electrode 2 when the molar ratio of L is 0.1 to 0.7. That is, (L x E 1-x ) y (G) O 3 (0.1 ≦ x ≦ 0.7, 0.9 ≦ y ≦ 1.05) is particularly preferable.

尚、第２材料は電子伝導性を有するものであれば、酸素イオン伝導性を同時に有する材料であっても構わない。第２材料は、隣接する他の材料（例えば第１材料）と固相反応を起こさない材料であることが好ましく、例えば固体酸化物形燃料電池の空気極２として従来用いられている材料、例えばランタノイド・マンガナイト系ペロブスカイト型酸化物（Ｌｎ１−ｙＭｎＯ３または（Ｌｎ１−ｘ，Ｅｘ）１−ｙＭｎＯ３）の利用が好ましい。上記組成式の中のＬｎはランタノイド（即ち、Ｌａ，Ｃｅ，Ｐｒ，Ｎｄ，Ｓｍ，Ｅｕ，Ｇｄ，Ｔｂ，Ｄｙ，Ｈｏ，Ｅｒ，Ｔｍ，Ｙｂ，Ｌｕのいずれか）であり、Ｅは、アルカリ土類金属元素または当該アルカリ土類金属元素の一部が他の１もしくは複数のアルカリ土類金属元素で置換されたものであり、０＜ｘ≦０．７、−０．０５≦ｙ≦０．１である。例えば１０００℃で作動するＳＯＦＣにおいては、１０００℃の作動条件下で化学的に安定で且つ電子伝導性の高い（Ｌａ１−ｘＳｒｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘＣａｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘ（Ｓｒ１−ｚＣａｚ）ｘ）１−ｙＭｎＯ３（但し、０＜ｘ≦０．７、−０．０５≦ｙ≦０．１、０＜ｚ＜１）が第２材料として最適である。例えば本実施形態では、ランタン・ストロンチウム・マンガナイトＬａ０．６Ｓｒ０．４ＭｎＯ３（ＬＳＭ）を第２材料として用いる。 The second material may be a material having oxygen ion conductivity at the same time as long as it has electron conductivity. The second material is preferably a material that does not cause a solid phase reaction with another adjacent material (for example, the first material), for example, a material conventionally used as the air electrode 2 of the solid oxide fuel cell, for example, Use of a lanthanoid manganite-based perovskite oxide (Ln 1-y MnO 3 or (Ln 1-x , E x ) 1-y MnO 3 ) is preferred. Ln in the above composition formula is a lanthanoid (that is, any one of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), and E is an alkali. An earth metal element or a part of the alkaline earth metal element is substituted with one or more other alkaline earth metal elements, and 0 <x ≦ 0.7, −0.05 ≦ y ≦ 0 .1. For example, in an SOFC operating at 1000 ° C., (La 1-x Sr x ) 1-y MnO 3 or (La 1-x Ca x ) that is chemically stable and has high electron conductivity under the operating condition of 1000 ° C. 1-y MnO 3 or (La 1-x (Sr 1 -z Ca z) x) 1-y MnO 3 ( where, 0 <x ≦ 0.7, -0.05 ≦ y ≦ 0.1,0 < z <1) is optimal as the second material. For example, in the present embodiment, lanthanum, strontium, manganite La 0.6 Sr 0.4 MnO 3 (LSM) is used as the second material.

例えば本実施形態では第１材料としてのＹＳＺを２つの群に分け、当該分けた一方の群に対して焼成処理を施すようにしている。当該焼成処理を施したＹＳＺは、燃料電池の高温作動条件下（１０００℃程度）で焼結し難くなる難焼結性を示す。この難焼結性を良好に得るために、当該焼成処理は例えば１２００℃〜１６００℃の高温で行うことが好ましく、１４００℃以上の高温で行うことが最も好ましい。また、焼成時間は１０時間以上とすることが好ましい。上記焼成処理を施したＹＳＺを仮焼ＹＳＺと呼ぶ。一方、上記焼成処理を施していないＹＳＺを未焼成ＹＳＺと呼ぶ。   For example, in the present embodiment, YSZ as the first material is divided into two groups, and one of the divided groups is subjected to a firing process. YSZ that has been subjected to the firing treatment exhibits a low sinterability that makes it difficult to sinter under high temperature operating conditions (about 1000 ° C.) of the fuel cell. In order to obtain this hardly sinterability satisfactorily, the baking treatment is preferably performed at a high temperature of, for example, 1200 ° C. to 1600 ° C., and most preferably performed at a high temperature of 1400 ° C. or higher. Moreover, it is preferable that baking time shall be 10 hours or more. YSZ that has been subjected to the above baking treatment is referred to as pre-fired YSZ. On the other hand, YSZ that has not been subjected to the above firing treatment is referred to as unfired YSZ.

仮焼材料６としての仮焼ＹＳＺ、未焼成材料７としての未焼成ＹＳＺ、基材料８としてのＬＳＭは、例えばボールミルや乳鉢などの粉砕機や粉砕具を用いて粉末状とする。仮焼ＹＳＺの粒子径は、１μｍ〜２０μｍの範囲、好ましくは１μｍ〜１０μｍ程度の粒度分布とする。上記粒子条件にあてはまるＹＳＺを細ＹＳＺと呼ぶ。一方、未焼成ＹＳＺの粒子径は、仮焼ＹＳＺの粒子径よりも小さいものとし、例えば１μｍ以下、好ましくは０．１μｍ〜１μｍ程度の粒度分布とする。上記粒子条件にあてはまるＹＳＺを微ＹＳＺと呼ぶ。ＬＳＭ粒子の粒子径は、例えば１μｍ以下、好ましくは０．１μｍ〜１μｍ程度とする。例えば本実施形態では、仮焼ＹＳＺの粒子径を３μｍ程度とし、ＬＳＭ粒子の粒子径を１μｍ程度とし、未焼成ＹＳＺの粒子径を０．４μｍ程度とする。したがって本実施形態においては、「細ＹＳＺの粒子径＞ＬＳＭ粒子の粒子径＞微ＹＳＺの粒子径」となる関係が成立する。ここで、粒子径は例えば粒子の最大わたし径を指すものとする。   The calcined YSZ as the calcined material 6, the unfired YSZ as the unfired material 7, and the LSM as the base material 8 are made into a powder form using a pulverizer or pulverizer such as a ball mill or a mortar. The particle size of the calcined YSZ is in the range of 1 μm to 20 μm, preferably about 1 μm to 10 μm. YSZ that meets the above particle conditions is referred to as fine YSZ. On the other hand, the particle size of the unfired YSZ is smaller than the particle size of the calcined YSZ, for example, 1 μm or less, preferably about 0.1 μm to 1 μm. YSZ that meets the above particle conditions is referred to as fine YSZ. The particle diameter of the LSM particles is, for example, 1 μm or less, preferably about 0.1 μm to 1 μm. For example, in this embodiment, the particle size of the calcined YSZ is set to about 3 μm, the particle size of the LSM particles is set to about 1 μm, and the particle size of the unfired YSZ is set to about 0.4 μm. Therefore, in the present embodiment, the relationship of “fine YSZ particle diameter> LSM particle diameter> fine YSZ particle diameter” is established. Here, the particle diameter refers to, for example, the maximum particle diameter of the particles.

仮焼材料６としての仮焼ＹＳＺ、未焼成材料７としての未焼成ＹＳＺ、基材料８としてのＬＳＭを混合するに際しては、仮焼材料６の質量混合比が未焼成材料７の質量混合比よりも大きく、仮焼材料６と基材料８と未焼成材料７とからなる全体に対する基材料８の体積混合率が４０％以上６０％以下の範囲となり、仮焼材料６（細ＹＳＺ）：基材料８（ＬＳＭ粒子）：未焼成材料７（微ＹＳＺ）が、質量比でｘ：（１０−ｘ）：１となるように混合することが好ましい。特に、第１材料としてＹＳＺを用い、第２材料としてＬＳＭを用いる本実施形態においては、仮焼材料６（細ＹＳＺ）：基材料８（ＬＳＭ粒子）：未焼成材料７（微ＹＳＺ）が、質量比で４：６：１となるように、混合することが好ましい。尚、上記混合に際しては、特に特殊な混合法を用いる必要はなく、例えばボールミルや乳鉢などを用いた一般的な混合法を採用できる。   When mixing the calcined YSZ as the calcined material 6, the unfired YSZ as the unfired material 7, and the LSM as the base material 8, the mass mixing ratio of the calcined material 6 is greater than the mass mixing ratio of the unfired material 7. The volume mixing ratio of the base material 8 with respect to the whole composed of the calcined material 6, the base material 8, and the unfired material 7 is in the range of 40% to 60%, and the calcined material 6 (fine YSZ): base material 8 (LSM particles): The unfired material 7 (fine YSZ) is preferably mixed so that the mass ratio is x: (10−x): 1. In particular, in this embodiment using YSZ as the first material and LSM as the second material, calcined material 6 (fine YSZ): base material 8 (LSM particles): unfired material 7 (fine YSZ), It is preferable to mix such that the mass ratio is 4: 6: 1. In the above mixing, it is not necessary to use a special mixing method. For example, a general mixing method using a ball mill or a mortar can be employed.

仮焼材料６（細ＹＳＺ）と基材料８（ＬＳＭ粒子）と未焼成材料７（微ＹＳＺ）の混合物を用いて電解質１上に空気極２を形成する方法は特に限定されず、既存のまたは新規の方法を適宜採用できる。例えば本実施形態では、細ＹＳＺとＬＳＭ粒子と微ＹＳＺよりなる上記粉体の混合物に、テレビン油とα−テレピネオールを添加してスラリー化し、このスラリーをテープキャスト法で電解質１上に塗布し、その後、空気中で１，２００℃で１．５時間焼成して電解質１上に空気極２を形成する。尚、テレビン油とα−テレピネオールの質量比は１：４とし、添加するテレビン油とα−テレピネオールの合計体積が、細ＹＳＺとＬＳＭ粒子と微ＹＳＺよりなる上記粉体の混合物の体積と同程度となるようにする。但し、テレビン油とα−テレピネオールの混合物を用いる必要は必ずしもなく、テレビン油やその他の分散剤を単独で使用しても良い。また、スラリー化に際して、増孔剤などの添加剤を更に添加するようにしても良い。尚、ＳＯＦＣの構造や形状等は図８の例に限定されず、他の既知又は新規の構造や形状を適宜採用してよい。   The method of forming the air electrode 2 on the electrolyte 1 using a mixture of the calcined material 6 (fine YSZ), the base material 8 (LSM particles), and the unfired material 7 (fine YSZ) is not particularly limited, New methods can be employed as appropriate. For example, in this embodiment, turpentine oil and α-terpineol are added to a mixture of the above powders composed of fine YSZ, LSM particles and fine YSZ to form a slurry, and this slurry is applied onto the electrolyte 1 by a tape casting method, and then The air electrode 2 is formed on the electrolyte 1 by baking in air at 1,200 ° C. for 1.5 hours. The mass ratio of turpentine oil and α-terpineol is 1: 4, and the total volume of turpentine oil and α-terpineol to be added is approximately the same as the volume of the above-mentioned powder mixture composed of fine YSZ, LSM particles, and fine YSZ. Like that. However, it is not always necessary to use a mixture of turpentine oil and α-terpineol, and turpentine oil or other dispersants may be used alone. Moreover, you may make it add additives, such as a pore-forming agent, at the time of slurrying. Note that the structure, shape, and the like of the SOFC are not limited to the example shown in FIG.

上述した材料選定条件および粒度条件および質量比条件に従って、仮焼材料６（細ＹＳＺ）と基材料８（ＬＳＭ粒子）と未焼成材料７（微ＹＳＺ）が混合されてなる多孔質混合伝導体５によれば、図１に示すように、細ＹＳＺ粒子と微ＹＳＺ粒子によって空気極２内に骨格構造が形成され、その内部にガス拡散路としての気孔、ならびに電流パスと電極反応場を決定するＬＳＭ粒子がそれぞれ連続的に分散配置したミクロ構造が形成される。この多孔質混合伝導体５によれば、１０００℃程度の作動条件下でＳＯＦＣの空気極２に求められる以下の条件を満足する。即ち、（１）電子伝導性が高く、（２）酸素イオン生成の反応場を有し（換言すれば、酸素の吸着能を有し）、（３）焼結し難く多孔質が維持でき、（４）熱力学的に安定であり、（５）他の構成材料との化学反応性が小さく（換言すれば、両立性が大きく）、（６）電解質１と熱膨張率が同程度である。さらに、多孔質混合伝導体５は酸素イオン伝導性と電子伝導性との混合伝導性を示すので、空気極２としてのより好ましい性能を備える。   Porous mixed conductor 5 in which calcined material 6 (fine YSZ), base material 8 (LSM particles), and unfired material 7 (fine YSZ) are mixed according to the material selection conditions, particle size conditions, and mass ratio conditions described above. As shown in FIG. 1, a skeletal structure is formed in the air electrode 2 by fine YSZ particles and fine YSZ particles, and pores as gas diffusion paths, current paths, and electrode reaction fields are determined therein. A microstructure in which the LSM particles are continuously dispersed and formed is formed. According to this porous mixed conductor 5, the following conditions required for the SOFC air electrode 2 under the operating condition of about 1000 ° C. are satisfied. That is, (1) high electron conductivity, (2) a reaction field for oxygen ion generation (in other words, oxygen adsorption ability), (3) it is difficult to sinter and maintain a porous structure, (4) thermodynamically stable, (5) low chemical reactivity with other constituent materials (in other words, high compatibility), and (6) thermal expansion coefficient similar to that of the electrolyte 1. . Furthermore, since the porous mixed conductor 5 exhibits mixed conductivity of oxygen ion conductivity and electron conductivity, the porous mixed conductor 5 has more preferable performance as the air electrode 2.

しかも仮焼された細ＹＳＺが難焼結性を示し、ＬＳＭ粒子を主とする空気極構成粒子の凝集を防ぐ。これにより、１０００℃程度の高温且つ長時間の作動条件下でも、気孔率の低下、電極反応場の減少、ガス拡散の阻害を防ぎ、空気極２全体の性能劣化を防ぐ。これにより、空気極２の経時安定性が実現される。Ｎｉを用いた燃料極３に比べ、空気極２に由来する抵抗が大きいため、空気極２の抵抗は燃料電池の内部抵抗成分全体の半分以上を占めているが、空気極２の経時的な性能低下の問題を解決することで、ＳＯＦＣ全体の性能を向上させることができる。   Moreover, the calcined fine YSZ exhibits poor sinterability and prevents agglomeration of air electrode constituent particles mainly composed of LSM particles. This prevents a decrease in porosity, a decrease in electrode reaction field, an inhibition of gas diffusion, and a deterioration in performance of the entire air electrode 2 even under a high temperature and long-time operating condition of about 1000 ° C. Thereby, the temporal stability of the air electrode 2 is realized. Since the resistance derived from the air electrode 2 is larger than that of the fuel electrode 3 using Ni, the resistance of the air electrode 2 accounts for more than half of the entire internal resistance component of the fuel cell. By solving the problem of performance degradation, the performance of the entire SOFC can be improved.

本発明の有効性を確認するため、実際に多孔質混合伝導体５を用いて空気極２を作製し、以下の実験を行った。   In order to confirm the effectiveness of the present invention, the air electrode 2 was actually produced using the porous mixed conductor 5 and the following experiment was performed.

＜空気極材料の作製＞
本実施例では、スプレードライヤー法を用いて粒子径１μｍのＬａ０．６Ｓｒ０．４ＭｎＯ３を合成した。スプレードライヤー法により、均一で粒径の小さい酸化物微粒子を製造することが出来る。上記得られたＬＳＭ粉末を１０００℃で３時間仮焼した後、常温Ｘ線回析装置により単一相の確認を行った。上記仮焼により、Ｌａ，Ｓｒ，Ｍｎの酸化物が均一に分散されている状態からペロブスカイト型酸化の単一相が得られる。また、１４００℃で１０時間焼成したＺｒ０．９２Ｙ０．０８Ｏ２をボールミルで粉砕して粒子径３μｍの仮焼細ＹＳＺ粒子を得た。また、未焼成のＺｒ０．９２Ｙ０．０８Ｏ２をボールミルで粉砕して粒子径０．４μｍの未焼成微ＹＳＺ粒子を得た。細ＹＳＺの粒度分布は１．２μｍ〜６．５μｍであり、微ＹＳＺの粒度分布は０．２μｍ〜０．７μｍであった。尚、上記のＬＳＭ粉末に対する仮焼は、ペロブスカイト型酸化物を得るための処理であり、難焼結性を付与するためのＹＳＺに対する焼成処理とは目的を異にする。 <Production of air electrode material>
In this example, La 0.6 Sr 0.4 MnO 3 having a particle diameter of 1 μm was synthesized using a spray dryer method. Oxide fine particles having a uniform and small particle diameter can be produced by a spray dryer method. The obtained LSM powder was calcined at 1000 ° C. for 3 hours, and then a single phase was confirmed by a room temperature X-ray diffraction apparatus. By the calcination, a single phase of perovskite type oxidation is obtained from a state in which oxides of La, Sr, and Mn are uniformly dispersed. Further, Zr 0.92 Y 0.08 O 2 fired at 1400 ° C. for 10 hours was pulverized by a ball mill to obtain calcined fine YSZ particles having a particle diameter of 3 μm. Further, unfired Zr 0.92 Y 0.08 O 2 was pulverized with a ball mill to obtain unfired fine YSZ particles having a particle diameter of 0.4 μm. The particle size distribution of fine YSZ was 1.2 μm to 6.5 μm, and the particle size distribution of fine YSZ was 0.2 μm to 0.7 μm. The calcination of the LSM powder is a treatment for obtaining a perovskite oxide, and has a different purpose from the firing treatment for YSZ for imparting difficult sintering properties.

上記の仮焼細ＹＳＺ粒子とＬＳＭ粒子と未焼成微ＹＳＺ粒子を、質量比で４：６：１となる条件で、ボールミルで混合した。当該混合物をＬＭ４６１と呼ぶ。   The calcined fine YSZ particles, the LSM particles, and the unfired fine YSZ particles were mixed by a ball mill under the condition that the mass ratio was 4: 6: 1. This mixture is called LM461.

また、比較例として、仮焼細ＹＳＺ粒子とＬＳＭ粒子と未焼成微ＹＳＺ粒子を、質量比で２：８：１となる条件で、ボールミルで混合した。当該混合物をＬＭ２８１と呼ぶ。さらに、もう１つの比較例として、仮焼細ＹＳＺ粒子とＬＳＭ粒子と未焼成微ＹＳＺ粒子を、質量比で３：７：１となる条件で、ボールミルで混合した。当該混合物をＬＭ３７１と呼ぶ。上記のように本実施例では、仮焼材料（仮焼細ＹＳＺ粒子）と基材料（ＬＳＭ粒子）の合計と、未焼成材料（未焼成微ＹＳＺ粒子）の質量比が、１０：１となるようにした。   Further, as a comparative example, calcined fine YSZ particles, LSM particles, and unfired fine YSZ particles were mixed by a ball mill under the condition that the mass ratio was 2: 8: 1. This mixture is called LM281. Furthermore, as another comparative example, the calcined fine YSZ particles, the LSM particles, and the unfired fine YSZ particles were mixed by a ball mill under the condition that the mass ratio was 3: 7: 1. This mixture is called LM371. As described above, in this example, the mass ratio of the calcined material (calcined fine YSZ particles) and the base material (LSM particles) to the unfired material (unfired fine YSZ particles) is 10: 1. I did it.

＜実験１＞
上記のＬＭ４６１、ＬＭ２８１、ＬＭ３７１をそれぞれ用いて、図２に示す電解質１’上に空気極２’を形成し、ハーフセルを作製した。上記電解質１’には、株式会社日本触媒製のＹＳＺシート（２０φｍｍ×２００μｍ）を用いた。和光純薬工業株式会社製のα−テレピネオールとテレビン油を４：１で混合した溶液を、それぞれＬＭ４６１、ＬＭ２８１、ＬＭ３７１にほぼ同体積添加してペースト化し、各ペーストをそれぞれ別に用意したＹＳＺシート上にテープキャスト法で塗布し、空気中、１２００℃で１．５時間焼成して、作用極（ＷＥ）としての空気極２を作製した。田中貴金属工業株式会社製の白金（Ｐｔ）ペースト（ＴＲ−７０９１）に綜研化学株式会社製のＭＸ−３００（架橋アクリル粉体）を造孔剤として質量重量比で５％添加した多孔性Ｐｔペーストを対極（ＣＥ）に、田中貴金属工業株式会社製のＰｔペースト（ＴＲ−７６０３Ｔ）を参照極（ＲＥ）に用いて、それぞれの電極に焼き付けて三端子電極を作製した。図２中の符号９はＰｔ製の参照極（ＲＥ）を示し、符号１０はＰｔ製の対極（ＣＥ）を示す。 <Experiment 1>
Using the above LM461, LM281, and LM371, an air electrode 2 ′ was formed on the electrolyte 1 ′ shown in FIG. 2 to produce a half cell. As the electrolyte 1 ′, a YSZ sheet (20φ × 200 μm) manufactured by Nippon Shokubai Co., Ltd. was used. Wako Pure Chemical Industries, Ltd. α-terpineol and turpentine mixed in a 4: 1 solution were added to LM461, LM281, and LM371 in approximately the same volume to form a paste, and each paste was prepared on a YSZ sheet prepared separately. The air electrode 2 as a working electrode (WE) was produced by coating by a tape casting method and baking in air at 1200 ° C. for 1.5 hours. Porous Pt paste in which MX-300 (cross-linked acrylic powder) manufactured by Soken Chemical Co., Ltd. is added as a pore-forming agent at 5% by mass to platinum (Pt) paste (TR-7091) manufactured by Tanaka Kikinzoku Kogyo Co., Ltd. Was used as a counter electrode (CE), and a Pt paste (TR-7603T) manufactured by Tanaka Kikinzoku Kogyo Co., Ltd. was used as a reference electrode (RE). Reference numeral 9 in FIG. 2 indicates a reference electrode (RE) made of Pt, and reference numeral 10 indicates a counter electrode (CE) made of Pt.

ＬＭ４６１、ＬＭ２８１、ＬＭ３７１を用いて作製された各ハーフセルについて、定常分極測定（電流−電圧測定）を行った。図３にＬＭ４６１、ＬＭ２８１、ＬＭ３７１の定電位（ＷＥ−ＲＥ）における電流の時間依存性を示す。測定条件は、空気中、温度１０００℃で行った。時間は、定電位測定を開始した時間を基準としている。また、印加したカソード電位は−２００ｍＶ（ＬＭ２８１、ＬＭ３７１）と−１５０ｍＶ（ＬＭ４６１）とした。図３中の▽で示すプロットがＬＭ４６１の結果を示し、○で示すプロットがＬＭ２８１の結果を示し、△で示すプロットがＬＭ３７１の結果を示す。   Steady polarization measurement (current-voltage measurement) was performed on each half cell manufactured using LM461, LM281, and LM371. FIG. 3 shows the time dependency of the current at the constant potential (WE-RE) of LM461, LM281, and LM371. The measurement conditions were in air at a temperature of 1000 ° C. The time is based on the time when the constant potential measurement is started. The applied cathode potential was -200 mV (LM281, LM371) and -150 mV (LM461). In FIG. 3, the plot indicated by ▽ indicates the result of LM461, the plot indicated by ◯ indicates the result of LM281, and the plot indicated by Δ indicates the result of LM371.

ＬＭ２８１とＬＭ３７１については、分極開始後、通電効果（通電により、電流の通路が形成され、抵抗が低減する効果）と考えられる電流増加が確認された。そしてＬＭ２８１は３５時間後から、ＬＭ３７１は２時間後から、不規則に、それぞれ電流値の減少（即ち電極性能の劣化）が見られた。それに対して、ＬＭ４６１は、電流値は６０時間経過しても一定であり、時間経過に伴う性能劣化が見られず、経時安定性を示している。   With respect to LM281 and LM371, an increase in current that was considered to be an energization effect (an effect of forming a current path by energization and reducing resistance) was confirmed after the start of polarization. In addition, the current value decreased irregularly (that is, the electrode performance deteriorated) after 35 hours for LM281 and 2 hours for LM371. On the other hand, the current value of LM461 is constant even after 60 hours have passed, and no performance deterioration is observed with the passage of time, indicating stability over time.

表１に、仮焼材料と基材料と未焼成材料の質量比と、多孔質混合伝導体全体（即ち、仮焼材料と基材料と未焼成材料とからなる全体）に対する基材料の体積混合率（％）の関係を示す。表１には、（１）仮焼材料および未焼成材料に８ＹＳＺ（５．９ｇ／ｃｍ３）を用い、基材料にＬａ０．６Ｓｒ０．４ＭｎＯ３（６．３８ｇ／ｃｍ３）を用いた場合（即ち本実施例の場合）、（２）仮焼材料および未焼成材料に８ＹＳＺ（５．９ｇ／ｃｍ３）を用い、基材料にＬａＭｎＯ３（６．９２ｇ／ｃｍ３）を用いた場合、（３）仮焼材料および未焼成材料にＬａ０．６Ｓｒ０．４ＭｎＯ３（６．３８ｇ／ｃｍ３）を用い、基材料に８ＹＳＺ（５．９ｇ／ｃｍ３）を用いた場合、（４）仮焼材料および未焼成材料にＬａＭｎＯ３（６．９２ｇ／ｃｍ３）を用い、基材料に８ＹＳＺ（５．９ｇ／ｃｍ３）を用いた場合、の４通りを示す。
Table 1 shows the mass ratio of the calcined material, the base material, and the unfired material, and the volume mixing ratio of the base material to the entire porous mixed conductor (that is, the whole composed of the calcined material, the base material, and the unfired material). (%) Relationship is shown. Table 1, the (1) provisional baked material and green material with 8YSZ (5.9g / cm 3), La 0.6 Sr 0.4 MnO 3 based material (6.38 g / cm 3) when using (i.e. in the present example), use the (2) using 8YSZ the calcined material and the unfired material (5.9g / cm 3), LaMnO 3 based material (6.92 g / cm 3) If you were, it was used (3) with La 0.6 Sr 0.4 MnO 3 in calcined material and green material (6.38 g / cm 3), 8YSZ based material (5.9 g / cm 3) If, (4) LaMnO 3 using (6.92g / cm 3) in calcining the material and the unfired material, the use of 8YSZ (5.9g / cm 3) based material, showing the four types of.

ＬＭ４６１，ＬＭ３７１，ＬＭ２８１における基材料（Ｌａ０．６Ｓｒ０．４ＭｎＯ３）の体積混合率は、それぞれ５３％，６２％，７１％である。ＬＭ４６１において優れた経時安定性が得られたが、ＬＭ２８１およびＬＭ３７１では経時安定性が得られなかった上記実験結果から、経時安定性を得るための基材料の体積混合率の上限は、ＬＭ３７１の場合（６２％）と、ＬＭ４６１の場合（５３％）の間にあると推測される。一方で、経験則により、ＬＳＭの体積混合率は５０％前後が良いことは周知の事実である。体積混合率の上限が６２％の近傍にあり、体積混合率５０％が極大を示すのならば、基材料の体積混合率は、４０〜６０％が好ましく、４５〜５５％がより好ましいと考えられる。したがって、表１の太線で囲むケースに該当する多孔質混合伝導体においても優れた経時安定性が得られる可能性がある。 The volume mixing ratios of the base material (La 0.6 Sr 0.4 MnO 3 ) in LM461, LM371, and LM281 are 53%, 62%, and 71%, respectively. Excellent stability with time was obtained with LM461, but stability with time was not obtained with LM281 and LM371. From the above experimental results, the upper limit of the volume mixing ratio of the base material for obtaining stability over time is the case with LM371. (62%) and LM461 (53%). On the other hand, as a rule of thumb, it is a well-known fact that the volume mixing ratio of LSM should be around 50%. If the upper limit of the volume mixing ratio is in the vicinity of 62% and the volume mixing ratio of 50% shows a maximum, the volume mixing ratio of the base material is preferably 40 to 60%, more preferably 45 to 55%. It is done. Therefore, even with a porous mixed conductor corresponding to the case surrounded by the thick line in Table 1, excellent temporal stability may be obtained.

＜実験２＞
上記のＬＭ４６１を用いて、図４に示す単セルを形成し、発電特性と経時安定性について評価した。ここで用いた単セルは、インターコネクタを成膜していないセルを用いた。燃料極材料には、仮焼した粒子径２７μｍのＹＳＺと、粒子径１μｍのＮｉＯと、未焼成の粒子径０．６μｍのＹＳＺとを、４：６：１の質量比で混合した材料を用いた。電解質材料には、スカンジア安定化ジルコニア（ＳＳＺ：Ｚｒ０．８９Ｓｃ０．１Ｃｅ０．０１Ｏ２）を用いた。 <Experiment 2>
Using the LM461, a single cell shown in FIG. 4 was formed, and the power generation characteristics and stability over time were evaluated. The single cell used here was a cell in which no interconnector was formed. As the fuel electrode material, a material obtained by mixing calcined YSZ with a particle size of 27 μm, NiO with a particle size of 1 μm, and YSZ with an unfired particle size of 0.6 μm in a mass ratio of 4: 6: 1 is used. It was. The electrolyte material, scandia-stabilized zirconia: using (SSZ Zr 0.89 Sc 0.1 Ce 0.01 O 2).

上記燃料極材料を用いて直径４０ｍｍ、厚さ２．５ｍｍのペレットを作製し、１４００℃で１０時間焼成したものを、燃料極基板３として用いた。また、上記電解質材料をスラリー化し、燃料極基板３の片面および側面にスラリーコートで塗布し、１４００℃で焼成し、十数回塗布と焼成を繰り返して、電解質膜１を成膜した。そして、電解質膜１上に、上記のＬＭ４６１をテープキャスト法で塗布し、１２００℃で１．５時間焼成し、直径２ｃｍの空気極２を作製した。   A pellet having a diameter of 40 mm and a thickness of 2.5 mm was prepared using the above fuel electrode material, and was fired at 1400 ° C. for 10 hours, and used as the fuel electrode substrate 3. The electrolyte material was slurried, applied to one side and side surfaces of the fuel electrode substrate 3 by slurry coating, baked at 1400 ° C., and repeatedly applied and baked ten times to form the electrolyte membrane 1. And said LM461 was apply | coated by the tape-cast method on the electrolyte membrane 1, and it baked at 1200 degreeC for 1.5 hours, and produced the air electrode 2 with a diameter of 2 cm.

また比較例として、上記ＬＭ４６１の代わりに（Ｌａ０．８Ｓｒ０．２）０．９７ＭｎＯ３単体で構成される空気極２を有する単セルを形成した。この単セルを従来セルと呼ぶ。従来セルの電解質１にはＺｒ０．９２Ｙ０．０８Ｏ２（ＹＳＺ）を用いた。尚、ＹＳＺとＳＳＺの違い、およびＬａ０．６Ｓｒ０．４ＭｎＯ３と（Ｌａ０．８Ｓｒ０．２）０．９７ＭｎＯ３の違いによる電極反応のメカニズムに大きな違いはない。 As a comparative example, a single cell having an air electrode 2 composed of (La 0.8 Sr 0.2 ) 0.97 MnO 3 alone was formed instead of the LM461. This single cell is called a conventional cell. Zr 0.92 Y 0.08 O 2 (YSZ) was used for the electrolyte 1 of the conventional cell. The difference of YSZ and SSZ, and La 0.6 Sr 0.4 MnO 3 and (La 0.8 Sr 0.2) there is no big difference in 0.97 MnO 3 Differences in by electrode reaction mechanism.

対極（ＣＥ）と参照極（ＲＥ）として燃料極３に、Ｐｔ網と二本のＰｔ線をエヌ・イー・ケムキャット株式会社製のＰｔペースト（Ｕ−３４０１）で塗布し、１０００℃で０．５時間焼成した。発電の性能評価は、負荷装置（定電圧電源：高砂製作所 GP010-50R、電子負荷装置：高砂製作所 ERL600D）を用いて測定した。   As a counter electrode (CE) and a reference electrode (RE), a Pt net and two Pt wires are applied to the fuel electrode 3 with Pt paste (U-3401) manufactured by N.E. Baked for 5 hours. The performance evaluation of power generation was measured using a load device (constant voltage power supply: Takasago Seisakusho GP010-50R, electronic load device: Takasago Seisakusho ERL600D).

電気化学的測定のセル配置を図５に示す。発電条件は、１０００℃で行い、２５℃で加湿した純水素を０．３Ｌ／ｍｉｎで燃料極３へ導入し、１Ｌ／ｍｉｎで空気を空気極２へ導入した。図４，図５中の符号１１は参照極（ＲＥ）を示し、符号１２はＰｔ網を示し、符号１３はシール材を示し、符号１４はアルミナチューブを示し、矢印Ａは空気の流れを示し、矢印Ｂは水素の流れを示す。   The cell layout for electrochemical measurement is shown in FIG. The power generation conditions were 1000 ° C., pure hydrogen humidified at 25 ° C. was introduced into the fuel electrode 3 at 0.3 L / min, and air was introduced into the air electrode 2 at 1 L / min. 4 and 5, reference numeral 11 indicates a reference electrode (RE), reference numeral 12 indicates a Pt net, reference numeral 13 indicates a sealing material, reference numeral 14 indicates an alumina tube, and arrow A indicates the flow of air. , Arrow B indicates the flow of hydrogen.

図６にＬＭ４６１を用いて空気極２を形成した本発明に係る単セルと、従来セルの発電性能の時間依存性を示す。尚、ＬＭ４６１を用いた本発明に係る単セルについては８００時間経過後に電流密度を１Ａ／ｃｍ２から１．２Ａ／ｃｍ２に変えた。従来セルについては電流密度を１．２Ａ／ｃｍ２一定とした。図６中の○で示すプロットが電流密度１Ａ／ｃｍ２の時のＬＭ４６１を用いた新空気極の結果を示し、□で示すプロットが電流密度１．２Ａ／ｃｍ２の時のＬＭ４６１を用いた新空気極の結果を示し、●で示すプロットが従来セル（旧空気極）の結果を示す。 FIG. 6 shows the time dependency of the power generation performance of the single cell according to the present invention in which the air electrode 2 is formed using the LM461 and the conventional cell. For the single cell according to the present invention using LM461, the current density was changed from 1 A / cm 2 to 1.2 A / cm 2 after 800 hours. For the conventional cell, the current density was constant at 1.2 A / cm 2 . In FIG. 6, the plot indicated by ◯ indicates the result of the new air electrode using the LM461 when the current density is 1 A / cm 2 , and the plot indicated by □ uses the LM461 when the current density is 1.2 A / cm 2 . The results for the new air electrode are shown, and the plots marked with ● show the results for the conventional cell (old air electrode).

ＬＭ４６１を用いた本発明に係る単セルでは、２００時間まで通電効果と思われる電圧の増加が見られ、その後安定し、さらに電流密度を１．２Ａ／ｃｍ２に変えた後も安定している。即ち、ＬＭ４６１を用いた本発明に係る単セルでは、時間経過に伴う性能劣化が見られない。それに対して、従来セルは、時間に対して電圧の低下が顕著である。これにより本発明の有効性が確認された。 In the single cell according to the present invention using LM461, an increase in voltage that seems to be a current-carrying effect was observed up to 200 hours, and then stabilized, and even after the current density was changed to 1.2 A / cm 2 . . That is, in the single cell according to the present invention using the LM461, there is no performance deterioration over time. On the other hand, the voltage drop of the conventional cell is remarkable with respect to time. This confirmed the effectiveness of the present invention.

＜実験３＞
上記のＬＭ４６１における仮焼した粒子径３μｍのＹＳＺ粒子の代わりに、仮焼した粒子径４０μｍのＹＳＺ粒子を用いた空気極２を作製したところ、充分な電極性能が得られず、経時安定性についても問題があった。本願発明者が走査電子顕微鏡（ＳＥＭ）で空気極２内のミクロ構造を調べたところ、空孔や亀裂が多数あり、均一な構造が得られていないことが確認された。このため、電極反応場の減少や電子伝導パスの切断などを引き起こし、充分な性能が得られなかったと考えられる。図７に粒子径４０μｍの仮焼ＹＳＺ粒子を用いた場合の空気極２のＳＥＭ写真を示す。上記実験結果から、粒子径が２０μｍを超える仮焼ＹＳＺ粒子は、ＬＳＭ粒子の凝集防止効果として適当ではないと考えられる。 <Experiment 3>
When the air electrode 2 was prepared using YSZ particles having a calcined particle diameter of 40 μm instead of the calcined YSZ particles having a particle diameter of 3 μm in the above-described LM461, sufficient electrode performance was not obtained, and stability over time There was also a problem. When the inventor of the present application examined the microstructure in the air electrode 2 with a scanning electron microscope (SEM), it was confirmed that there were many holes and cracks and a uniform structure was not obtained. For this reason, it is considered that sufficient performance could not be obtained due to a decrease in the electrode reaction field and a break in the electron conduction path. FIG. 7 shows an SEM photograph of the air electrode 2 when calcined YSZ particles having a particle diameter of 40 μm are used. From the above experimental results, it is considered that the calcined YSZ particles having a particle diameter exceeding 20 μm are not suitable as an effect of preventing aggregation of LSM particles.

なお、上述の実施形態は本発明の好適な実施の一例ではあるがこれに限定されるものではなく、本発明の要旨を逸脱しない範囲において種々変形実施可能である。例えば、本発明の多孔質混合伝導体は、固体酸化物形燃料電池の空気極材料としての利用に限定されない。多孔質を維持しながら酸素イオン伝導性または電子伝導性を示す材料を必要とするＳＯＦＣ以外の装置の構成部材として利用しても良い。   The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, the porous mixed conductor of the present invention is not limited to use as an air electrode material of a solid oxide fuel cell. You may utilize as a structural member of apparatuses other than SOFC which requires the material which shows oxygen ion conductivity or electronic conductivity, maintaining a porosity.

また、上述の実施形態では、酸素イオン伝導性を備える第１材料としてＹＳＺを用い、電子伝導性を備える第２材料としてＬＳＭを用いた例について説明したが、これは好適な一例であって、この例に限定されるものではない。例えばＹＳＺの代わりに、装置の作動条件下（例えばＳＯＦＣの空気極としての利用であれば１０００℃程度の高温条件下）で化学的・熱力学的に安定な他の酸素イオン伝導性材料を用いても構わない。同様に、ＬＳＭの代わりに、装置の作動条件下（例えばＳＯＦＣの空気極としての利用であれば１０００℃程度の高温条件下）で化学的・熱力学的に安定な他の電子伝導性材料を用いても構わない。この際、第１材料は電子伝導性を同時に有する材料であってもよく、第２材料は酸素イオン伝導性材料を同時に有する材料であってもよい。多孔質混合伝導体を構成する諸材料についての先に説明した粒度条件および混合条件は、第１材料としてＹＳＺを用い且つ第２材料としてＬＳＭを用いる場合以外でも、第１材料が酸素イオン伝導性を主として備え且つ第２材料が電子伝導性を主として備えるとの条件を満たす限り、妥当すると考えられる。即ち、ＹＳＺ、ＬＳＭをそれぞれ作動温度下で同様の物性や機能を備える材料に置換した場合でも、先に説明した粒度条件および混合条件が当てはまると考えられる。例えば、コスト削減のため、ランタン系材料の原料となるＬａの代わりに、ランタン中間生成物原料（ランタンコンセレート）を用いても良い。また、低温（６００〜８００℃）用のＳＯＦＣに本発明の多孔質混合伝導体を用いる場合には、第１材料としてビスマス系酸化物を用いても良い。   Further, in the above-described embodiment, an example in which YSZ is used as the first material having oxygen ion conductivity and LSM is used as the second material having electron conductivity has been described. It is not limited to this example. For example, instead of YSZ, use another oxygen ion conductive material that is chemically and thermodynamically stable under the operating conditions of the device (for example, at a high temperature of about 1000 ° C. for use as an SOFC air electrode). It doesn't matter. Similarly, instead of LSM, other electronically conductive materials that are chemically and thermodynamically stable under the operating conditions of the apparatus (for example, at a high temperature of about 1000 ° C. when used as an SOFC air electrode) are used. You may use. At this time, the first material may be a material having electron conductivity at the same time, and the second material may be a material having an oxygen ion conductive material at the same time. The particle size conditions and mixing conditions described above for the materials constituting the porous mixed conductor are the same as those in the case where YSZ is used as the first material and LSM is used as the second material. As long as the condition that the second material mainly has electronic conductivity is satisfied. That is, even when YSZ and LSM are each replaced with a material having the same physical properties and functions at the operating temperature, it is considered that the particle size conditions and the mixing conditions described above apply. For example, in order to reduce costs, a lanthanum intermediate product raw material (lanthanum concealate) may be used instead of La as a raw material of the lanthanum-based material. Moreover, when using the porous mixed conductor of this invention for SOFC for low temperature (600-800 degreeC), you may use a bismuth-type oxide as a 1st material.

また上述の実施形態では、第１材料としてのＹＳＺを、仮焼ＹＳＺと未焼成ＹＳＺの２つの群に分け、第２材料としてのＬＳＭを基材料８としたが、第２材料（例えばＬＳＭ）を仮焼材料６と未焼成材料７の２つの群に分け、第１材料（例えばＹＳＺ）を基材料８としても良い。特に、仮焼材料６と基材料８と未焼成材料７の質量混合比を４：６：１とする場合、表１に示したように、多孔質混合伝導体５を構成する仮焼材料６と未焼成材料７の和と基材料８とはほぼ同体積となり、多孔質混合伝導体５における第１材料と第２材料の体積比はほぼ同等となるため、第１材料（例えばＹＳＺ）と第２材料（例えばＬＳＭ）を置換しても、同様の効果が得られると考えられるからである。尚、ＬＳＭを仮焼材料と未焼成材料とし、ＹＳＺを基材料とする場合、ＬＳＭの仮焼材料とは、焼成により得られたペロブスカイト型酸化物ＬＳＭに対して、難焼結性とするために更に焼成処理を施した材料を指し、ＬＳＭの未焼成材料とは、焼成により得られたペロブスカイト型酸化物ＬＳＭそのもの（難焼結性とするための更なる焼成は施していない材料）を指す。   In the above-described embodiment, YSZ as the first material is divided into two groups of calcined YSZ and unfired YSZ, and LSM as the second material is used as the base material 8, but the second material (for example, LSM) Are divided into two groups of calcined material 6 and unfired material 7, and the first material (for example, YSZ) may be used as the base material 8. In particular, when the mass mixing ratio of the calcined material 6, the base material 8, and the unfired material 7 is 4: 6: 1, as shown in Table 1, the calcined material 6 constituting the porous mixed conductor 5 is used. And the unfired material 7 and the base material 8 have substantially the same volume, and the volume ratio of the first material and the second material in the porous mixed conductor 5 is substantially the same, so that the first material (for example, YSZ) This is because it is considered that the same effect can be obtained even when the second material (for example, LSM) is replaced. When LSM is a calcined material and an unsintered material, and YSZ is a base material, the LSM calcined material is difficult to sinter to the perovskite oxide LSM obtained by firing. In addition, the LSM unfired material refers to the perovskite oxide LSM obtained by firing (a material that has not undergone further firing to make it difficult to sinter). .

本発明の多孔質混合伝導体のミクロ構造のモデルを示す図である。It is a figure which shows the model of the microstructure of the porous mixed conductor of this invention. 本発明の有効性を確認するための実験に用いたハーフセルの構造を示し、（Ａ）は平面図を示し、（Ｂ）は側面図を示す。The structure of the half cell used for the experiment for confirming the effectiveness of this invention is shown, (A) shows a top view, (B) shows a side view. 図２に示すハーフセルを用いた実験結果（電流の時間依存性）を示す。The experimental result (time dependence of an electric current) using the half cell shown in FIG. 2 is shown. 本発明の有効性を確認するための実験に用いた単セルの構造を示し、（Ａ）は平面図を示し、（Ｂ）は側面図を示す。The structure of the single cell used for the experiment for confirming the effectiveness of this invention is shown, (A) shows a top view, (B) shows a side view. 図４に示す単セルを用いた実験装置を示す構成図である。It is a block diagram which shows the experimental apparatus using the single cell shown in FIG. 図５に示す実験装置を用いた実験結果（セルの発電性能の時間依存性）を示す。The experimental result (time dependence of the power generation performance of a cell) using the experimental apparatus shown in FIG. 5 is shown. 仮焼した粒子径４０μｍのＹＳＺ粒子を用いて作製した空気極の走査電子顕微鏡写真である。It is the scanning electron micrograph of the air electrode produced using the YSZ particle | grains with a particle diameter of 40 micrometers which calcinated. 固体酸化物形燃料電池の構成例を示す斜視図である。It is a perspective view which shows the structural example of a solid oxide fuel cell.

符号の説明Explanation of symbols

１ 電解質
２ 空気極
３ 燃料極
４ インターコネクタ
５ 多孔質混合伝導体
６ 仮焼材料（細ＹＳＺ）
７ 未焼成材料（微ＹＳＺ）
８ 基材料（ＬＳＭ） DESCRIPTION OF SYMBOLS 1 Electrolyte 2 Air electrode 3 Fuel electrode 4 Interconnector 5 Porous mixed conductor 6 Calcination material (fine YSZ)
7 Unfired material (fine YSZ)
8 Base material (LSM)

Claims (13)

酸素イオン伝導性を備える第１材料と電子伝導性を備える第２材料との一方を、２つの群に分け、当該分けた一方の群に対して焼成処理を施しこれを仮焼材料とし、他方の未焼成の群を未焼成材料とし、前記第１材料と前記第２材料のうち上記焼成と未焼成の区別のない材料を基材料として、前記仮焼材料および前記基材料および前記未焼成材料を粉体とし、前記仮焼材料の粒子径を１μｍ〜２０μｍの範囲とし、前記未焼成材料の粒子径は前記仮焼材料の粒子径よりも小さいものとし、前記仮焼材料の質量混合比が前記未焼成材料の質量混合比よりも大きく、前記仮焼材料と前記基材料と前記未焼成材料とからなる全体に対する前記基材料の体積混合率が４０％以上６０％以下の範囲となる条件で、前記仮焼材料および前記基材料および前記未焼成材料が混合されてなる酸素イオン伝導性と電子伝導性を併せ持つ多孔質混合伝導体。   One of the first material having oxygen ion conductivity and the second material having electron conductivity is divided into two groups, and the one divided group is subjected to a baking treatment to be a calcined material, and the other The unsintered group is an unsintered material, and the calcined material, the base material, and the unsintered material are the base material of the first material and the second material that is not distinguished from the fired and unsintered materials. , The particle size of the calcined material is in the range of 1 μm to 20 μm, the particle size of the unfired material is smaller than the particle size of the calcined material, and the mass mixing ratio of the calcined material is The condition is such that the volume mixing ratio of the base material with respect to the whole composed of the calcined material, the base material, and the unfired material is in a range of 40% or more and 60% or less than the mass mixing ratio of the unfired material. The calcined material and the base material and the A porous mixed conductor having both oxygen ion conductivity and electron conductivity formed by mixing unfired materials. 前記仮焼材料と前記基材料と前記未焼成材料の質量混合比が、ｘ：（１０−ｘ）：１である請求項１記載の多孔質混合伝導体。   The porous mixed conductor according to claim 1, wherein a mass mixing ratio of the calcined material, the base material, and the unfired material is x: (10−x): 1. 前記第１材料は、ジルコニウム系酸化物（ＺｒＯ２または（Ｚｒ１−ｘ，Ａｘ）Ｏ２）、セリウム系酸化物（ＣｅＯ２または（Ｃｅ１−ｘ，Ａｘ）Ｏ２）、ビスマス系酸化物（δ−Ｂｉ２Ｏ３またはδ−（Ｂｉ１−ｘ，Ａｘ）２Ｏ３）、ランタン系酸化物（Ｌａ２Ｏ３または（Ｌａ１−ｘ，Ａｘ）２Ｏ３）、ハフニウム系酸化物（ＨｆＯ２または（Ｈｆ１−ｘ，Ａｘ）Ｏ２）、２Ａ族・３Ａ族元素系ガリウム酸化物（（Ｌ）１−ｚＧａＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｇａ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系アルミ酸化物（（Ｌ）１−ｚＡｌＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ａｌ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系コバルト酸化物（（Ｌ）１−ｚＣｏＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｃｏ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系鉄酸化物（（Ｌ）１−ｚＦｅＯ３または（Ｌ１−ｘ，Ｂｘ）１−ｚ（Ｆｅ１−ｙ，Ｄｙ）Ｏ３）、２Ａ族・３Ａ族元素系ジルコニウム酸化物（（Ｌ）２（１−ｚ）Ｚｒ２Ｏ７または（Ｌ１−ｘ，Ｂｘ）２（１−ｚ）（Ｚｒ１−ｙ，Ｄｙ）２Ｏ７）、２Ａ族・３Ａ族元素系チタン酸化物（（Ｂ）１−ｚＴｉＯ３または（Ｂ１−ｘ，Ｌｘ）１−ｚ（Ｔｉ１−ｙ，Ｍｙ）Ｏ３）のいずれかであり、前記Ａは放射性元素を除く価数２＋あるいは価数３＋の金属元素、または前記価数２＋あるいは価数３＋の金属元素の一部が１もしくは複数の他の前記価数２＋あるいは価数３＋の金属元素で置換されたものであり、前記Ｂは放射性元素を除く２Ａ族元素または前記２Ａ族元素の一部が１もしくは複数の他の前記２Ａ族元素で置換されたものであり、前記ＤはＰｔと放射性元素を除く第４周期、第５周期、第６周期の遷移金属元素、またはアルカリ土類金属元素、または前記遷移金属元素あるいはアルカリ土類金属元素の一部が１もしくは複数の他の前記遷移金属元素あるいはアルカリ土類金属元素で置換されたものであり、前記Ｌは放射性元素を除く３Ａ族の遷移金属元素または前記３Ａ族元素の一部が１もしくは複数の他の前記３Ａ族元素で置換されたものであり、前記Ｍは１Ａ族およびＨｇおよび放射性元素を除く典型金属元素または前記典型金属元素の一部が１もしくは複数の他の前記典型金属元素で置換されたものであり、０＜ｘ≦１、０＜ｙ＜１、−０．０５≦ｚ≦０．１である請求項１または２記載の多孔質混合伝導体。 The first material is a zirconium-based oxide (ZrO 2 or (Zr 1-x , A x ) O 2 ), a cerium-based oxide (CeO 2 or (Ce 1-x , A x ) O 2 ), or a bismuth-based material. Oxide (δ-Bi 2 O 3 or δ- (Bi 1-x , A x ) 2 O 3 ), lanthanum oxide (La 2 O 3 or (La 1-x , A x ) 2 O 3 ), Hafnium-based oxide (HfO 2 or (Hf 1-x , A x ) O 2 ), Group 2A / 3A group element-based gallium oxide ((L) 1-z GaO 3 or (L 1-x , B x ) 1-z (Ga 1-y , D y ) O 3 ), Group 2A / 3A group element aluminum oxide ((L) 1-z AlO 3 or (L 1-x , B x ) 1-z (Al 1-y , D y ) O 3 ), group 2A / 3A group elemental cobalt oxide ((L) 1-z CoO 3 or (L 1-x , B x ) 1-z (Co 1-y , D y ) O 3 ), group 2A / group 3A element-based iron oxide ((L) 1-z FeO 3 or (L 1 -x, B x) 1-z (Fe 1-y, D y) O 3), 2A group · 3A group elements-based zirconium oxide ((L) 2 (1- z) Zr 2 O 7 or (L 1 -x, B x) 2 (1 -z) (Zr 1-y, D y) 2 O 7), 2A group · 3A group elements-based titanium oxide ((B) 1-z TiO 3 or (B 1- x , L x ) 1-z (Ti 1-y , M y ) O 3 ), wherein A is a valence 2+ or valence 3+ metal element excluding radioactive elements, or the valence 2+ or A part of the metal element having a valence of 3+ is substituted with one or a plurality of other valence 2+ or valence 3+ metal elements, B is a group 2A element excluding radioactive elements or a part of the group 2A element substituted with one or more other group 2A elements, and D is a fourth period excluding Pt and radioactive elements, The transition metal element or alkaline earth metal element of the fifth period or the sixth period, or a part of the transition metal element or alkaline earth metal element is one or more other transition metal elements or alkaline earth metal elements Wherein L is a group 3A transition metal element excluding radioactive elements, or a part of the group 3A element is substituted with one or more other group 3A elements; Is a typical metal element excluding Group 1A and Hg and radioactive elements, or a part of the typical metal element is substituted with one or more other typical metal elements, and 0 <x ≦ 1, 0 <y < 1 The porous mixed conductor according to claim 1, wherein −0.05 ≦ z ≦ 0.1. 前記第１材料は、イットリア安定化ジルコニアまたはスカンジア安定化ジルコニアまたはスカンジア安定化ジルコニアのスカンジウムの一部がセリウムで置換されたものである請求項１または２記載の多孔質混合伝導体。   3. The porous mixed conductor according to claim 1, wherein the first material is obtained by replacing part of scandium of yttria-stabilized zirconia, scandia-stabilized zirconia, or scandia-stabilized zirconia with cerium. 前記第２材料は、２Ａ族・３Ａ族元素系ペロブスカイト型酸化物（（Ｌ）１−ｙ（Ｇ）Ｏ３または（Ｌ１−ｘ，Ｅｘ）１−ｙ（Ｇ）Ｏ３）であり、前記Ｌは放射性元素を除く３Ａ族の遷移金属元素または前記３Ａ族元素の一部が１もしくは複数の他の前記３Ａ族元素で置換されたものであり、前記Ｅはアルカリ土類金属元素または当該アルカリ土類金属元素の一部が他の１もしくは複数のアルカリ土類金属元素で置換されたものであり、前記ＧはＰｔと放射性元素を除く第４周期、第５周期、第６周期の遷移金属元素または前記遷移金属元素の一部が他の１もしくは複数の上記遷移金属元素で置換されたものであり、０＜ｘ≦１、−０．０５≦ｙ≦０．１である請求項１から４のいずれか１つに記載の多孔質混合伝導体。 The second material is a group 2A-3A element-based perovskite oxide ((L) 1-y (G) O 3 or (L 1-x , E x ) 1-y (G) O 3 ). , L is a group 3A transition metal element excluding radioactive elements, or a part of the group 3A element is substituted with one or more other group 3A elements, and E is an alkaline earth metal element or A part of the alkaline earth metal element is replaced with one or more other alkaline earth metal elements, and G is the fourth period, the fifth period, and the sixth period excluding Pt and the radioactive element. The transition metal element or a part of the transition metal element is substituted with one or more other transition metal elements, and 0 <x ≦ 1, −0.05 ≦ y ≦ 0.1 5. The porous mixed conductor according to any one of 1 to 4. 前記第２材料は、ランタノイド・マンガナイト系ペロブスカイト型酸化物（Ｌｎ１−ｙＭｎＯ３または（Ｌｎ１−ｘ，Ｅｘ）１−ｙＭｎＯ３）であり、前記Ｌｎはランタノイドまたは当該ランタノイドの一部が他の１もしくは複数のランタノイドで置換されたものであり、前記Ｅはアルカリ土類金属元素または当該アルカリ土類金属元素の一部が他の１もしくは複数のアルカリ土類金属元素で置換されたものであり、０＜ｘ≦０．７、−０．０５≦ｙ≦０．１である請求項１から４のいずれか１つに記載の多孔質混合伝導体。 The second material is a lanthanoid-manganite perovskite oxide (Ln 1-y MnO 3 or (Ln 1-x , E x ) 1-y MnO 3 ), and the Ln is a lanthanoid or one of the lanthanoids. Part is substituted with one or more other lanthanoids, and E is an alkaline earth metal element or a part of the alkaline earth metal element is substituted with one or more other alkaline earth metal elements The porous mixed conductor according to claim 1, wherein 0 <x ≦ 0.7 and −0.05 ≦ y ≦ 0.1. 前記第２材料は、（Ｌａ１−ｘＳｒｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘＣａｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘ（Ｓｒ１−ｚＣａｚ）ｘ）１−ｙＭｎＯ３（但し、０＜ｘ≦０．７、−０．０５≦ｙ≦０．１、０＜ｚ＜１）である請求項１から４のいずれか１つに記載の多孔質混合伝導体。 Said second material, (La 1-x Sr x ) 1-y MnO 3 or (La 1-x Ca x) 1-y MnO 3 or (La 1-x (Sr 1 -z Ca z) x) 1 -y MnO 3 (where, 0 <x ≦ 0.7, -0.05 ≦ y ≦ 0.1,0 <z <1) a porous mixed according to any one of the 4 claims 1 Conductor. 前記第１材料はイットリア安定化ジルコニアＺｒ０．９２Ｙ０．０８Ｏ２であり、前記第２材料はランタン・ストロンチウム・マンガナイトＬａ０．６Ｓｒ０．４ＭｎＯ３であり、前記仮焼材料と前記基材料と前記未焼成材料の質量混合比が４：６：１である請求項１記載の多孔質混合伝導体。 The first material is yttria-stabilized zirconia Zr 0.92 Y 0.08 O 2 , the second material is lanthanum, strontium, manganite La 0.6 Sr 0.4 MnO 3 , and the calcined material The porous mixed conductor according to claim 1, wherein a mass mixing ratio of the base material and the unfired material is 4: 6: 1. 前記未焼成材料および前記基材料の粒子径は１μｍ以下である請求項１から８のいずれか１つに記載の多孔質混合伝導体。   The porous mixed conductor according to any one of claims 1 to 8, wherein a particle diameter of the unfired material and the base material is 1 µm or less. 前記焼成処理は１２００℃〜１６００℃で行われる請求項１から９のいずれか１つに記載の多孔質混合伝導体。   The porous mixed conductor according to any one of claims 1 to 9, wherein the firing treatment is performed at 1200 ° C to 1600 ° C. 請求項１から１０のいずれか１つに記載の多孔質混合伝導体を用いることを特徴とする固体酸化物形燃料電池の空気極材料。   An air electrode material for a solid oxide fuel cell, wherein the porous mixed conductor according to any one of claims 1 to 10 is used. イットリア安定化ジルコニアまたはスカンジア安定化ジルコニアまたはスカンジア安定化ジルコニアのスカンジウムの一部がセリウムで置換されたものを酸素イオン伝導性材料として、この酸素イオン伝導性材料を２つの群に分け、当該分けた一方の群に対して１２００℃〜１６００℃で焼成処理を施しこれを仮焼材料とし、他方の未焼成の群を未焼成材料とし、（Ｌａ１−ｘＳｒｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘＣａｘ）１−ｙＭｎＯ３または（Ｌａ１−ｘ（Ｓｒ１−ｚＣａｚ）ｘ）１−ｙＭｎＯ３（但し、０＜ｘ≦０．７、−０．０５≦ｙ≦０．１、０＜ｚ＜１）を基材料として、前記仮焼材料および前記基材料および前記未焼成材料を粉体とし、前記仮焼材料の粒子径を１μｍ〜２０μｍの範囲とし、前記未焼成材料および前記基材料の粒子径は１μｍ以下とし、前記仮焼材料と前記基材料と前記未焼成材料の質量混合比が４：６：１となる条件で、前記仮焼材料および前記基材料および前記未焼成材料が混合されて、酸素イオン伝導性と電子伝導性を併せ持つ多孔質体として形成されることを特徴とする固体酸化物形燃料電池の空気極材料。 Ytria-stabilized zirconia or scandia-stabilized zirconia or scandia-stabilized zirconia in which part of scandium is substituted with cerium is used as an oxygen ion-conductive material, and the oxygen ion-conductive material is divided into two groups. One group is subjected to a baking treatment at 1200 ° C. to 1600 ° C. to be a calcined material, and the other unfired group is an unfired material, and (La 1-x Sr x ) 1-y MnO 3 or ( La 1-x Ca x) 1 -y MnO 3 or (La 1-x (Sr 1 -z Ca z) x) 1-y MnO 3 ( where, 0 <x ≦ 0.7, -0.05 ≦ y ≦ 0.1, 0 <z <1) as a base material, the calcined material, the base material, and the unfired material are powders, and the calcined material has a particle diameter in a range of 1 μm to 20 μm, Unburnt The particle size of the material and the base material is 1 μm or less, and the calcined material, the base material, and the base material, and the base material and the unfired material have a mass mixing ratio of 4: 6: 1. An air electrode material for a solid oxide fuel cell, wherein the unfired material is mixed to form a porous body having both oxygen ion conductivity and electron conductivity. 酸素イオン伝導性を備える第１材料と電子伝導性を備える第２材料との一方を、２つの群に分け、当該分けた一方の群に対して焼成処理を施しこれを仮焼材料とし、他方の未焼成の群を未焼成材料とし、前記第１材料と前記第２材料のうち上記焼成と未焼成の区別のない材料を基材料として、前記仮焼材料および前記基材料および前記未焼成材料を粉体とし、前記仮焼材料の粒子径を１μｍ〜２０μｍの範囲とし、前記未焼成材料の粒子径は前記仮焼材料の粒子径よりも小さいものとし、前記仮焼材料の質量混合比は前記未焼成材料の質量混合比よりも大きく、前記仮焼材料と前記基材料と前記未焼成材料とからなる全体に対する前記基材料の体積混合率が４０％以上６０％以下の範囲となる条件で、前記仮焼材料および前記基材料および前記未焼成材料を混合して、酸素イオン伝導性と電子伝導性を併せ持つ多孔質混合伝導体を得ることを特徴とする多孔質混合伝導体の製造方法。   One of the first material having oxygen ion conductivity and the second material having electron conductivity is divided into two groups, and the one divided group is subjected to a baking treatment to be a calcined material, and the other The unsintered group is an unsintered material, and the calcined material, the base material, and the unsintered material are the base material of the first material and the second material that is not distinguished from the fired and unsintered materials. The particle size of the calcined material is in the range of 1 μm to 20 μm, the particle size of the unfired material is smaller than the particle size of the calcined material, and the mass mixing ratio of the calcined material is The condition is such that the volume mixing ratio of the base material with respect to the whole composed of the calcined material, the base material, and the unfired material is in a range of 40% or more and 60% or less than the mass mixing ratio of the unfired material. The calcined material and the base material and the A method for producing a porous mixed conductor, comprising mixing a green material to obtain a porous mixed conductor having both oxygen ion conductivity and electronic conductivity.
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JP2009016350A (en) * 2007-07-04 2009-01-22 Korea Inst Of Science & Technology Electrode/electrolyte composite powder for fuel cell, and its preparation method
JP2010282896A (en) * 2009-06-05 2010-12-16 Nippon Telegr & Teleph Corp <Ntt> Solid oxide fuel cell
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US8128988B2 (en) 2004-08-10 2012-03-06 Central Research Institute Of Electric Power Industry Film-formed article and method for producing same
JP2012164672A (en) * 2006-02-10 2012-08-30 Nippon Shokubai Co Ltd Air electrode material for solid oxide fuel cell
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US8128988B2 (en) 2004-08-10 2012-03-06 Central Research Institute Of Electric Power Industry Film-formed article and method for producing same
JP2012164672A (en) * 2006-02-10 2012-08-30 Nippon Shokubai Co Ltd Air electrode material for solid oxide fuel cell
JP2009016350A (en) * 2007-07-04 2009-01-22 Korea Inst Of Science & Technology Electrode/electrolyte composite powder for fuel cell, and its preparation method
EP2377192A4 (en) * 2008-12-19 2012-08-08 Saint Gobain Ceramics Reduction-oxidation-tolerant electrodes for solid oxide fuel cells
EP2377192A2 (en) * 2008-12-19 2011-10-19 Saint-Gobain Ceramics & Plastics Inc. Reduction-oxidation-tolerant electrodes for solid oxide fuel cells
JP2012513096A (en) * 2008-12-19 2012-06-07 サン−ゴバン セラミックス アンド プラスティクス，インコーポレイティド Reduction-oxidation resistant electrodes for solid oxide fuel cells
US8455153B2 (en) 2008-12-19 2013-06-04 Saint-Gobain Ceramics & Plastics, Inc. Reduction-oxidation-tolerant electrodes for solid oxide fuel cells
JP2012524956A (en) * 2009-04-24 2012-10-18 テクニカル・ユニヴァーシティ・オブ・デンマーク Composite oxygen electrode and method of manufacturing the same
JP2010282896A (en) * 2009-06-05 2010-12-16 Nippon Telegr & Teleph Corp <Ntt> Solid oxide fuel cell
JP2011009144A (en) * 2009-06-29 2011-01-13 National Institute Of Advanced Industrial Science & Technology Method for manufacturing solid oxide electrochemical cell
US8835061B2 (en) 2011-07-06 2014-09-16 Honda Motor Co., Ltd. Metal oxygen battery
DE102012211745B4 (en) * 2011-07-06 2014-12-24 Honda Motor Co., Ltd. Metal-oxygen battery
JP2016091857A (en) * 2014-11-06 2016-05-23 新日鐵住金株式会社 Air electrode of solid oxide type fuel cell, solid oxide type fuel cell, and method for manufacturing air electrode of solid oxide type fuel cell

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