The Effect of Post-Annealing on the Properties of a Pulsed-Laser-Deposited La0.6Sr0.4CoO3-delta-Ce0.9Gd0.1O2-delta Nano-Composite Cathode

Abstract

The effect of the post-annealing on the properties of the La0.6Sr0.4CoO3-delta-Ce0.9Gd0.1O2-delta (LSC-GDC) nano-composite cathode fabricated by pulsed laser deposition (PLD) is investigated. Implementing the post-annealing treatment at a temperature in the range of 800 degrees C similar to 1000 degrees C enables the control of the grain size in the LSC-GDC over the range of several tens of nanometers to near one-hundred nanometers. Moreover, the post-annealing treatment improves the interconnectivity between the same materials and mitigates the vertical separation between the columnar domains, resulting in the reduction of the lateral conduction loss. In terms of the electrochemical properties, the cathodic activity of the post-annealed cathode appears to be reduced due to the reduction in the number of the surface reaction sites, which is a result of the post-annealing grain-size growth. Although this grain-size growth results less power output of the solid oxide fuel cell (SOFC) using a post-annealed LSC-GDC cathode relative to that of the SOFC using the as-deposited LSC-GDC cathode, the lifetime of the former at 650 degrees C is improved. (C) 2013 The Electrochemical Society. All rights reserved.