Fibrous Mixed Conducting Cathode with Embedded Ionic Conducting Particles for Solid Oxide Fuel Cells

The Sm0.5Sr0.5CoO3-delta (SSC) fibers with embedded nano-Sm0.2Ce0.8O1.9 (SDC) particles are fabricated by electrospinning process using commercial SDC nanopowders and an SSC precursor gel containing polyvinyl alcohol (PVA) and aqueous metal nitrate. After calcination at 800 degrees C, fibers with diameters ranged between 300 and 500 nm and well-developed SSC cubic-perovskite structure and SDC fluorite are successfully obtained. The calculated crystallite sizes of SSC and SDC are 20.78 and 45.35 nm, respectively. Over whole measured temperature ranges during the symmetrical cell test, the fiber composite cathode exhibits much lower polarization resistance than conventional powder composite cathodes. The polarization resistances are estimated to 0.06 and 1.23 Omega cm(2) for the fiber composites and 0.15 and 2.10 Omega cm(2) for the powder composites at 700 and 550 degrees C, respectively. The single cell with the fiber composite cathode shows much higher performances; its maximum power density is 380.5 mW cm(-2) at 550 degrees C and higher than 1278 mW cm(-2) at 700 degrees C. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.