Transition Metal Doped Solid Oxide Fuel Cell Cathodes

Abstract

Fuel cells have developed of excessive interest as a probable economical, efficient, and clean candidate for alternative and environmental friendly power generation services. Solid Oxide Fuel Cell (SOFC) is an elevated temperature fuel cell, dealing with power generation as well as heat. Up to now many studies have been made to replace platinum, Pt, with a new cathode catalyst for intermediate temperature-solid oxide fuel cells (IT-SOFC) (500 °C<T) range but research has become inadequate. Since Pt sources are limited and very expensive, they could not meet the supply for the commercial fuel cells, the scientists started for searching new materials. There are two important aspects about SOFC cathodes, different cathode materials effect on the electrode electrochemical performance and the oxygen reduction reaction (ORR) kinetics. Understanding in these concepts would lead to improvements of SOFC systems. The production of novel and supreme cathode electrodes used in IT-SOFC is aimed to employ cheaper metals (Fe, Co, Cr, Mn, Gd, and V) by using superior properties of perovskite structure. The reduction of oxygen on metal oxide surface is achieved within the complicated mechanism. The completion of these steps depends on the nature of oxide ion carrier in cathode, atomic formation in crystal structure, and microstructure of cathode materials. The analysis of the impedances required the use of three to four (RQ) circuits in series in the equivalent circuit model. Of the four cathodes synthesized, the vanadium doped cathode on YSZ showed the highest area specific resistance.