(La,Sr)(Co,Fe)O3-(Ce,Gd)(Sr)O2 electrospun nanofiber composite cathode for solid oxide fuel cells

Abstract

La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF)-Ce_0.78Gd_0.2Sr_0.02O_2-δ (GDCSr) electrospun nanofibers composite cathode which was screen printed on GDCSr electrolytes were studied for application in intermediate temperature SOFC. Impedance spectroscopy measurements were performed in ambient air over a temperature range from 500-800°C. The addition of 20wt.% GDCSr nanofiber to LSCF resulted in an increasing of 40% porosity value which enhance the electrochemical properties by providing much amount of triple phase boundaries. The nanofiber composite cathode exhibits an increasing exchange current density and a decreasing cathode polarization resistance. Nanofiber GDCSr plays an important role as a porosity controller and an ionic pathway for oxygen ion diffusion inside the composite cathode structure.