ELECTROLYTE SHEET WITH REGIONS OF DIFFERENT COMPOSITIONS AND FUEL CELL DEVICE INCLUDING SUCH

摘要

An electrolyte sheet comprising two major surfaces, the electrolyte sheet including regions of differing compositions ( R1-R4 ), so that at least one of these regions Rl, R2, R3 has at least 1.5 times higher ionic conductivity than at least one other region R4; wherein the at least one other region R4 has 20% more tetragonal phase zirconia per volume than the least one region with higher ionic conductivity; and when viewed in cross-section taken through said major surfaces at least one of the regions exhibits a non-uniform thickness.