Morphology and electrochemical characterization of LaSrCuO4-δ|Ce0.9Gd0.1O2-δ interface

The electrochemical properties of LaSrCuO4-delta (LSCO) electrode screen-printed on Ce0.9Gd0.1O2-delta, (CGO) electrolyte have been investigated. The morphology of the LSCO vertical bar CGO interface was analyzed by scanning electron microscopy. The LSCO vertical bar CGO vertical bar LSCO symmetric cells with porous electrodes were studied by both AC impedance spectroscopy at OCV conditions and cyclic voltamperometry (CVA) in the temperature range of 500-900 degrees C at the oxygen partial pressures of 10(-4)-0.21 atm. The impedance response consisted of two depressed semicircular arcs which indicated that the overall electrode process included at least two distinguishable rate-determining steps of oxygen exchange process. It was found that the rate-determined steps of the overall electrode process changed at temperature around 700 degrees C. The area specific resistance (ASR) at the temperatures of 750-900 degrees C in air decreased in the range from 10 Omega cm(2) to 1 Omega cm(2). The ASR of the electrode cycled in the range of 500-900 degrees C for 5 days was stable for a long time under heat treatment that proved the electrochemical stability of the interface. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.