Proper oxygen reduction mechanism of NdBa0.5Sr0.5Co2O5+δ -Ce0.9Gd0.1O1.95 composite cathodes for intermediate temperature solid oxide fuel cell

Abstract

Electrochemical properties of composite cathode with NdBa0.5 Sr0.5Co2O5+δ (NBSCO) and Ce0.9Gd0.1O1.95 (GDC) are investigated for the intermediate temperature solid oxide fuel cell (IT-SOFC) application. NBSCO, as a mixed ionic and electronic conductor (MIEC), have got an attention as one of the best cathode materials because of their substantially high electrical conductivities and rapid oxygen exchange and diffusion characteristics. When it is combined with ceria based oxide, such as GDC, this composite can possess extended triple phase boundary (TPB) where the electrochemical reaction occurs, leading higher cell performance. Here we propose an oxygen reduction mechanism for NBSCO as a MIEC and GDC as an electrocatalyst to enhanced electrochemically active area. We also investigate the variation of the single cell performance for different ratio of the NBSCO and the GDC.