On the Suitability of La0.60Sr0.40Co0.20Fe0.80O3 Cathode for the Intermediate Temperature Solid Oxide Fuel Cell (ITSOFC)

Solid oxide fuel cell can convert fuels rich in H-2 into electrical energy directly without pollution by electrochemical reaction with oxygen. The efficiency of energy conversion and durability of performance mainly depend on the electrocatalytic activity of the cathode and its thermo-chemical compatibility with the oxide ion conducting solid electrolyte. The global experience gained all these years in the SOFC development has prompted for a change from the state of the art functional cathode material, La1-xSrMnO3 (LSM) to a new material which is an electrocatalyst for the oxygen reduction reaction in the intermediate temperature range (873-1073 K). In this work, La(0.60)Sr(0.40)Co(0.2)fe(0.80)O(3), (LSCF), a mixed conducting stable perovskite oxide prepared by glycine nitrate combustion route is systematically characterised. Both circular and rectangular pellets were fabricated by uniaxial compression followed by annealing at different temperatures. The functional properties such as porosity, percentage thermal shrinkage in volume and percentage densification of the sintered pellets are compiled. It is found that La0.60Sr0.40Co0.20Fe0.80O3 exhibited high electrical conductivity (350 Scm(-1)) at ITSOFC operating temperature (1073 K). The thermo-chemical compatibility of this cathode material with alternate oxide ion conducting solid electrolytes namely, La0.9Sr0.1Ga0.8Mg0.2O3, Ce0.90Gd0.10O2, and Ce0.80Sm0.20O2 ( LSGM, CDC and SDC respectively) is also brought out. A brief discussion is made on its suitability for application as electrocatalytic cathode under ITSOFC operating conditions