La0.8Sr0.2Fe0.8Cu0.2O3-δ as cobalt-free cathode for La0.8Sr0.2Ga0.8Mg0.2O3-δ electrolyte

A cobalt-free cathode material with stoichiometric composition La0.8Sr0.2Fe0.8Cu0.2O3-delta (LSFCu) was specifically developed for use with La0.8Sr0.2Ga0.8.Mg0.2O3-delta (LSGM) electrolyte in intermediate temperature solid oxide fuel cell (IT-SOFC) systems. The chemical stability of LSFCu in contact with LSGM electrolyte was investigated by structural and morphological analysis. The electrochemical properties of LSFCu dense pellets were investigated in the temperature range 600-750 degrees C by electrochemical impedance spectroscopy (EIS). LSFCu vertical bar LSGM vertical bar LSFCu symmetrical cells were prepared and area specific resistance (ASR) values, directly depending on the rate limiting step of the oxygen reduction reaction, were evaluated. Fuel cells were prepared using LSFCu as cathode material on a LSGM pellet and electrochemical tests were performed in the 700-800 degrees C temperature range and compared to similar fuel cells prepared by using commercial La0.6Sr0.4Fe0.8Co0.2O3-delta (LSFCo) as a cathode. The maximum current density and power density recorded for LSFCu and LSFCo were similar. This fact demonstrates that Cu can be used as Co substitute in perovskite cathode materials. (C) 2014 Elsevier B.V. All rights reserved.