Investigation of electrospun Ba0.5Sr0.5Co0.8Fe0.2O3-delta-Gd0.1Ce0.9O1.95 cathodes for enhanced interfacial adhesion

Abstract

Fibrous Ba0.5Sr0.5Co0.8Fe0.2O3-delta-Gd0.2Ce0.9O1.95 (BSCF-GDC) composite cathodes are fabricated by a facile electrospinning method. However, the electropun BSCF-GDC cathode shows poor adhesion to a GDC electrolyte because of the high shrinkage rate of the electrospun BSCF-GDC cathode during sintering. To solve this adhesion issue, mixed BSCF fiber-GDC powder cathode is investigated. As a result, mixed BSCF fiber-GDC powder cathode with an enhanced adhesion is successfully fabricated. This improvement can be attributed to the modified microstructure with the GDC powder that joins the BSCF fibers to the GDC electrolyte at the cathode and electrolyte interface. The polarization resistance of the mixed BSCF fiber-GDC powder cathode is 0.10 Omega cm(2), which is lower than 0.13 Omega cm(2) of conventional BSCF-GDC powder cathode at 700 degrees C. It is attributable to the improved oxygen gas and lattice oxygen diffusion, and the surface exchange of the mixed BSCF fiber-GDC powder cathode. The single cell with a mixed BSCF fiber-GDC powder cathode show 500 mW cm(-2) at 700 degrees C, which is 25% higher than conventional BSCF-GDC powder cathode. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.