ZIRCONIUM OXYGEN2 TYPE SOLID ELECTROLYTE MATERIAL WITH ADDITION OF RARE EARTH OXIDE, SCANDIUM 2 OXYGEN 3 AND ALUMINUM 2 OXYGEN 3

摘要

PROBLEM TO BE SOLVED: To provide a solid electrolyte material which can be prevented from undergoing aged deterioration as to ion conductivity even when used for a long time by achieving both high ion conductivity and crystalline structure stability through the resolution of problems with the solid solubility limit of Al2 O3 in a ZrO2 -Sc2 O3 -Al2 O3 type that serves as a conventional solid electrolyte material. SOLUTION: In a ZrO2 (zirconia) type solid electrolyte which contains Sc2 O3 as the main dopant and Al2 O3 as the auxiliary dopant, Yb2 O3 and/or Lu2 O3 are further added as trace amounts of dopants, the compositions of the additions being (1-x)(ZrO2 )-(x-y-z)(Sc2 O3 )-y(Al2 O3 )-z (1-a)(Yb2 O3 )-a(Lu2 O3 )} (0.07<=x<=0.13, 0.0005<=y<=0.006, 0.02-4y<=z<=0.04-4y, 0.0<=z, 0<=a<=1).