Patent ID: 8703346

Claim:
An electrolyte sheet for solid oxide fuel cell comprising: a plurality of concaves and/or convexes at least on one side of the electrolyte sheet, wherein plan-viewed shapes of the concaves or the convexes are approximately circular, elliptical, or polygonal with polygon's corners rounded and with polygon's corners having an at least 0.1 μm of curvature radius, and/or three-dimensional shapes of the concaves or the convexes are approximately hemispherical, hemi-ellipsoidal, or polyhedral with polyhedron's ridges or corners having curves of an at least 0.1 μm of curvature radius in cross-sectional views of the concaves or the convexes, wherein an average circle-equivalent diameter of the plan-viewed shapes of the concaves or the convexes is at least 0.5 μm and at most 250 μm, wherein an average depth of the concaves or an average height of the convexes is at least 0.3 μm and at most 50 μm, and wherein an average thickness of the electrolyte sheet is at least 100 μm and at most 400μm.