Concept and technology of SOFC for electric vehicles

A SOFC concept based on microtubular cells is presented. Mechanical tests and modelling show viability for fast thermal cycling in air for both zirconia and ceria electrolyte tubes. To combine advantages of both these materials, the concept includes a thin double layer electrolyte, with zirconia on the fuel side and ceria on the air side. This allows to use active cobaltite cathodes. The surface reaction mechanism of oxygen reduction on the cobaltite/ceria system was analysed and shown to be determined by dissociative adsorption rather than bulk incorporation. Cells based on this concept were fabricated, at present in an easier accessible planar configuration, for demonstration purposes, and shown to feature high power density at low operating temperature (0.8 W cm−2 at <800°C).