Electrochemical properties of ceria-based intermediate temperature solid oxide fuel cell using microwave heat-treated La0.1Sr0.9Co0.8Fe0.2O3-delta as a cathode

Abstract

The temperature dependence of the chemical diffusion coefficient and the surface exchange coefficient of LSCF1982 is successfully determined from the D.C. conductivity relaxation in the temperature range of 500 <= T/degrees C <= 700 and an oxygen partial pressure of 0.21 atm. The kinetic values of chemical diffusion coefficient (D) and surface exchange coefficient (k) are 1.85 x 10(-5) cm(2) s(-1) and 2.42 x 10(-4) cm s(-1) at 650 degrees C, respectively. The electrochemical properties of La0.1Sr0.9Co0.8Fe0.2O3-delta (LSCF1982) as a cathode for ceria based IT-SOFC are successfully characterized by I-V performance measurement and electrochemical impedance spectroscopy (EIS) in terms of cathode microstructure effects by using microwave heat treatment. The cell with microwave heat-treated cathode shows the higher performance than conventional heat treated cathode. At 650 degrees C the open circuit potential (OCP) and maximum power density are respectively 0.753 V and 1.79 W cm(-2) under 150 sccm of wet hydrogen and air gas flow conditions, and the ohmic and electrode area specific resistance (ASR) are 0.037 and 0.014 Omega cm(2), respectively. (C) 2012 Elsevier B.V. All rights reserved.