Perovskites used in fuel cells

Fuel cells are devices for energy generation with very high theoretical efficiency. Many researches were been carried out in the last few decades in order to develop reliable fuel cells. Solid oxide fuel cells (SOFC) and polymeric exchange membrane fuel cells (PEMFC) are those with more potential for commercial use. Specially for SOFC cathodes, many perovskites have been proposed as potential materials for this application. Nevertheless, other components of SOFC, such as the electrolytes, anodes and interconnects, have also been targeted with potential perovskites. More recently, the use of perovskites in PEMFC has also been proposed and studied. As many perovskite compositions can be used in SOFC components, some of the most important are discussed in this chapter and some recent works in perovskites for PEMFC are also referred. As a whole, in this chapter, the reader will find the relationship between the properties of perovskites with their compositions and the main effects of dopant agents regarding the utilization of these materials in different components of SOFC and in electrodes of PEMFC