Electrolyte-electrode joined assembly and method for producing the same

A method for producing an electrolyte-electrode joined assembly comprising an anode and a cathode with a solid electrolyte interposed therebetween, an intermediate layer being formed between the solid electrolyte and the cathode, the method comprising:

• the steps of forming the anode on one surface of the solid electrolyte directly or with another intermediate layer interposed therebetween, and thereafter forming the cathode on the other surface of the solid electrolyte with the intermediate layer interposed therebetween;
• or
• the steps of forming the solid electrolyte on one surface of the anode directly or with the other intermediate layer interposed therebetween, and thereafter forming the cathode on the solid electrolyte with the intermediate layer interposed therebetween,
• wherein
• the intermediate layer facing the cathode is formed as a porous body by forming particles into a formed body and thereafter preliminary-sintering the formed body,
• the porous body includes a pore opened on a surface facing the cathode,
• a pore diameter of the pore of the intermediate layer is at most 3 μm,
• a porosity of the intermediate layer is 25% to 40%,
• the cathode is formed as a laminate containing at least a first layer having one flat surface and a second layer disposed on the flat surface,
• the first layer contains a perovskite-type composite oxide represented by BaxSr1-xCoyFe1-yO3 or LaxSr1-xCoyFe1-yO3, where 0≦x≦1 and 0≦y≦1, and
• an open pore on a surface of the intermediate layer is filled with the first layer.

An electrolyte-electrode joined assembly comprising

• an anode and a cathode with a solid electrolyte interposed therebetween,
• an intermediate layer being formed between the solid electrolyte and the cathode, wherein
• the intermediate layer is a porous body and has a thickness of 0.2 to 10 μm,
• the cathode contains at least a first layer in contact with the intermediate layer and a second layer disposed on the first layer,
• the first layer has a thickness of 0.2 to 5 μm, contains a perovskite-type composite oxide represented by BaxSr1-xCoyFe1-3O3 or LaxSr1-xCoyFe1-yO3, where 0≦x≦1 and 0≦y≦1, and has one surface facing the second layer, the one surface being a flat surface,
• the intermediate layer has an open pore on a surface thereof facing the first layer, the pore being filled with the first layer, and
• the second layer has a thickness of 10 to 40 μm and is a porous body having a pore allowing passage of an oxygen-containing gas.