Film Blowing of Ceria Electrolyte Plates

A mechanically-ground doped ceria powder with 10 mol% SmO1.5 was incorporated by high shear mixing into a polystyrene-based organic vehicle. At 45 vol.% solids loading, the suspension could be subjected to elongational flow processes and was prepared in thin film form by tubular film blowing; the manufacturing process used to make thermoplastic polymer film. This provides a potential route for the manufacture of ceramic electrolyte plates for solid oxide fuel cells for which doped ceria is a candidate material. After sintering, film thickness down to 50 μm could be achieved with relative densities >95%. The main problem with this route is in retaining flatness of films of less than 100 μm in thickness during sintering; a problem which exists whatever the particle assembly route.