Toho Gas Co., Ltd.

Nippon Shokubai Co., Ltd.

Sumitomo Metal Mining Company, Ltd.

Kenji Ukai

Kouji Hisada

Yasunobu Mizutani

Kazuo Hata

Norikazu Aikawa

Masatoshi Shimomura

Hiroyuki Toya

Shoji Futaki

Misuzu Yokoyama

A powder material for a fuel electrode of a solid oxide fuel cell is provided, along with a fuel electrode for a solid oxide fuel cell prepared by sintering the fuel electrode powder material, and a solid oxide fuel cell including the fuel electrode. The fuel electrode powder material includes a nickel based powder material containing at least one of nickel and nickel oxide and at least one of titanium oxide (IV) and a titanium source capable of changing into titanium oxide (IV) by heat treatment in air.

Fuel electrode material, a fuel electrode, and a solid oxide fuel cell

A single cell for SOFC operating at low temperatures is provided, including a first solid electrolyte with oxide ion conductivity at 800&#xb0; C. of 0.015 S/cm or more and bending strength of 600 MPa or more, a fuel electrode and bonded to one side of the first electrolyte, comprised of a cermet of a catalyst and a second solid electrolyte with a conductivity of 0.08 S/cm or more, and an air electrode bonded to the other side of the first electrolyte comprised of a compound of first perovskite type oxide with a third solid electrolyte. The electrodes are coated with fuel and air electrode contact layers, respectively.

Single cell for a solid oxide fuel cell

A single cell for SOFC operating at low temperatures, is provided, including a first solid electrolyte with oxide ion conductivity at 800&#xb0; C. of 0.015 S/cm or more and bending strength of 600 MPa or more, a fuel electrode and bonded to one side of the first electrolyte, comprised of a cermet of a catalyst and a second solid electrolyte with a conductivity of 0.08 S/cm or more, and an air electrode bonded to the other side of the first electrolyte comprised of a compound of first perovskite type oxide with a third solid electrolyte. The electrodes are coated with fuel and air electrode contact layers, respectively.

A single cell for a solid oxide fuel cell and a solid oxide fuel cell using the same practicable and excellent in generation performance and durability, wherein a fuel electrode including a cermet of a catalyst and a second solid electrolyte with oxide ion conductivity at 1000&#xb0; C. of 0.20 S/cm or more is bonded to one side of a solid electrolyte plate with the conductivity of 0.07 S/cm or more and bending strength of 700 MPa or more, and an air electrode including a compound of perovskite type transition metal oxide with a third solid electrolyte is bonded to the other side. A surface of the fuel electrode is coated with a layer, and an air electrode surface is coated with a layer, and an aqueous solution where a noble metal compound is dissolved in water is impregnated into the air electrode.

The present invention intends to provide a solid oxide fuel cell having a supported electrolyte film, which shows sufficiently high reliability, yields a high output, and exhibits high output power density per unit volume. The present invention is characterized by use of a first cermet comprising catalyst and a second solid electrolyte, which has a bending strength of more than 500 MPa and exhibits oxide ion conductivity, for a fuel electrode substrate in an SOFC having a supported electrolyte film equipped with an electrolyte-electrode assembly that is made by bonding the fuel electrode substrate and an air electrode on both sides of an electrolyte film consisting of the first solid electrolyte capable of exhibiting oxide ion conductivity. As a preferred embodiment, stabilized zirconia containing 2 to 4 mol % yttria or 3 to 6 mol % scandia is preferred for the second solid electrolyte. More particularly, an interlayer comprising the second catalyst and the third solid electrolyte, which shows oxide ion conductivity of more than 0.1 S/cm at 800&deg; C., is preferably interposed between the electrolyte film and the fuel electrode substrate.

Solid oxide fuel cell having a supported electrolyte film

A solid oxide fuel cell in which the catalytic activity of a fuel electrode is high and in which no poisoning by carbon occurs even when internal reforming is performed under a condition of a low S/C ratio and further in which the time course degradation of the fuel electrode is less when internal reforming is performed. In a solid oxide fuel cell having an oxide ion conductive solid electrolyte, and a fuel electrode and an air electrode connected to both faces thereof, a cermet of a catalyst and of the second solid electrolyte whose oxide ion conductivity is more than or equal to 0.2 S/cm at 1000 &deg; C. is used as the fuel electrode. More specifically, it is desirable that the second solid electrolyte is scandia-stabilized zirconia (ScSZ) containing 9 to 12 mol % of scandia. In addition, the second solid electrolyte may further be ScSZ containing yttria or ceria less than or equal to 2 mol %. Furthermore, the second solid electrolyte may be a composite material of ScSZ and alumina less than or equal to 2 wt %.

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Tokai, Japan

Kenji Ukai