Concept and technology of SOFC for electric vehicles

A SOFC concept based on microtubular cells is presented. Mechanical tests a nd modelling show viability for fast thermal cycling in air for both zircon ia and ceria electrolyte tubes. To combine advantages of both these materia ls, 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 cobaltit e cathodes. The surface reaction mechanism of oxygen reduction on the cobal tite/ceria system was analysed and shown to be determined by dissociative a dsorption rather than bulk incorporation. Cells based on this concept were fabricated, at present in an easier accessible planar configuration, for de monstration purposes, and shown to feature high power density at low operat ing temperature (0.8 W cm(-2) at < 800 degrees C). (C) 2000 Elsevier Scienc e B.V. All rights reserved.