SOLID ELECTROLYTE ASSEMBLY HAVING INTERMEDIATE LAYER

A solid electrolyte assembly has an anode, a cathode, and a solid electrolyte layer located therebetween. An intermediate layer is provided between the anode or the cathode and the solid electrolyte layer. The intermediate layer is made of a cerium oxide containing lanthanum and a rare-earth element excluding lanthanum and cerium. The solid electrolyte layer contains an oxide of lanthanum. Preferably, the solid electrolyte layer contains a composite oxide of lanthanum and silicon. Also, preferably, the intermediate layer is made of a cerium oxide containing lanthanum and any one of samarium, gadolinium, yttrium, erbium, ytterbium, and dysprosium.