Electrochemical investigation of strontium doping effect on high performance Pr1-xSrxCoO3-delta (x=0.1, 0.3, 0.5, and 0.7) cathode for intermediate-temperature solid oxide fuel cells

Abstract

The Pr1-xSrCoO3-delta perovskite-type oxides have received extensive attention as a promising cathode material due to their favorable properties for realizing high performance intermediate temperature solid oxide fuel cells (IT-SOFCs). This study focuses on the electrical properties, electrochemical performance, and redox behavior of a perovskite oxide of Pr1-xSrxCoO3-delta (x = 0.1, 0.3, 0.5, and 0.7). For x= 0.1 and 0.3, the electrical conductivities increase with increasing strontium content. In the case of x > 0.3, however, decreased electrical conductivity is observed with increasing x. The oxygen non-stoichiometry of Pr1-xSrxCoO3-delta using coulometric titration and its electrical conductivity in a wide range of oxygen partial pressure at 973 K are also investigated. A Ni-GDC anode-supported cell is fabricated to evaluate the electrochemical performance of the Pr1-xSrxCoO3-delta cathode material. The maximum power density at 973 K is 1.19 W cm(-2) for x= 0.3, and the other samples also show high power density over 1.0 W cm-2, except for at x= 0.7. Given its high electrical conductivity and cell performance, Pr0.7Sr0.3CoO3-delta is a favorable cathode material candidate for IT-SOFC applications.