Enhanced SOFC cathode performance by infiltrating Ba0.5Sr0.5Co0.8Fe0.2O3 − δ nanoparticles for intermediate temperature solid oxide fuel cells

Abstract

Solid oxide fuel cells (SOFCs) as alternatives for energy conversion have exhibited some unique advantages such as wide fuel flexibility, high energy efficiency and exhaust heat. An innovative composite cathode for SOFCs consisting of a high conductive La0.7Sr0.3CuO3−δ (LSCu) electrode backbone infiltrated by nano and Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) particles with high electro-catalytic activity has been successfully fabricated by a simple solution infiltration process. The effect of BSCF nano catalyst on the electrochemical activity and stability of LSCu cathode was investigated and the inherent oxygen reduction reaction (ORR) mechanism is discussed. The polarization resistance is 0.043Ωcm2 for 15wt.% BSCF infiltrated LSCu cathode, and is reduced ~92.6% to that pure LSCu (0.58Ωcm2) at 700°C. The short term stability demonstrates that the electrochemical activity can be further improved in the first period about 40h at 700°C. After operated for 70h, the electrochemical performance of the composite cathode became stable. A conductive scaffold (e.g. LSCu) modified with a highly catalytic nano particles (e.g. BSCF) is an attractive approach to fabricate cathodes with high electrochemical performance and stability.