2. Thin films in SOFC, PCFC and MCFC devices

2.1 General features

SOFC operating temperatures typically range from 800 to 1,000°C. These high temperatures are necessary to achieve sufficient conductivity for the YSZ electrolyte and good electrode performance.

This is probably the major problem limiting the competitiveness of this technology, and has prompted much of the current research into SOFCs to reduce operating temperatures from the usual temperatures close to 1,000°C to lower temperatures in the 300-600°C range.

The reduction in operating temperature has enabled the progressive replacement of lanthanum chromite interconnection plates (a ceramic material which is very delicate to machine) with stainless steels. However, at lower temperatures, ionic conductivity decreases and...