Nanofibrous perovskite La0.35Pr0.15Sr0.5Fe0.8Ti0.2O3-δ as cathode for solid oxide fuel cells

Abstract

Nanofibrous and particulate Fe-based solid oxide fuel cells cathode materials of La_0.35Pr_0.15Sr_0.5Fe_0.8Ti_0.2O_3-δ (LPSFT) are prepared by electrostatic spinning method and citrate–nitrate combustion method to investigate the effect of different morphologies on electrochemical properties. SEM images reveal that LPSFT nanofibers exhibit a three-dimensional network structure, which enhances the transport of oxygen ions and electrons during the oxygen reduction reaction and improves the porosity and specific surface area of the cathode material, resulting in higher electrochemical performance than that of particulate LPSFT. At 800 °C, the polarization impedance (R_p) of the nanofibrous and particulate LPSFT cathodes are 0.17 Ω cm² and 0.33 Ω cm², respectively. The cell with nanofibrous LPSFT as the cathode has a peak power density (PPD) of 0.99 W cm⁻² at 800 °C when fueled by 3 % H₂O humidified hydrogen, which is almost twice that of the particulate LPSFT as the cell cathode (PPD of 0.50 W cm⁻²). It suggests that electrostatic spinning is an effective technique for improving the electrochemical properties of cathode materials.