Effect of a-Site Cation Defect on Electrochemical Performance and Stability of La_0.8Sr_0.2Co_0.2Fe_0.8O_{3- δ} Cathode

Abstract

The application of Solid oxide fuel cells (SOFCs) is restricted by the insufficient catalytic activity in oxygen reduction reaction and the impedance increase of cathode in long-term operation at medium and low temperature. In this work, we prepare La0.8Sr0.2Co0.2Fe0.8O3-δ (LSCF) nanofiber cathode material with different A-site defects by electrospinning technology, and systematically explore the influence of A-site cation defect on the electrochemical performance and long-term stability of LSCF cathode. La0.77Sr0.2Co0.2Fe0.8O3-δ, (La0.8Sr0.2)0.97Co0.2Fe0.8O3-δ and La0.8Sr0.17Co0.2Fe0.8O3-δ cathode materials are successfully prepared by controlling the proportion of nitrate input, among which La0.77Sr0.2Co0.2Fe0.8O3-δ obtains the best electrochemical performance, and the polarization impedance is 0.09 Ω·cm2 at 800 ℃.