International Journal of Hydrogen Energy, Vol.43, No.40, 18642-18649, 2018
One pot synthesis of (La,Sr)CoO3/(La,Sr)(2)CoO4 for IT-SOFCs cathodes
It is well known that hetero-interfaces in (La,Sr)CoO3/(La,Sr)(2)CoO4 (LSC113/214) are beneficial in catalyzing ORR for SOFC cathodes. This can be achieved by synthesizing the individual phases and mixing them together. In this study, so as to maximize the hetero interfaces, an alternative method was used in which one pot Pechini method was employed to synthesize a two-phase structure. LSC113/214 two phase structures from one precursors solution were successfully synthesized without the formation of any undesired third phase for the first time. It was found that a minimum temperature of 800 degrees C was necessary so as to obtain the fully crystallized dual phase powder. Two phase structures of molar fractions from 0.40 to 0.60 was targeted and were successfully obtained with some deviations. Impedance measurements were carried out on porous conventional symmetric cells fabricated with the synthesized dual phase powders between 400 and 700 degrees C. The dual phase powders had improved electrode performance as compared to single phase and physically mixed powders, but this was limited down to 500 degrees C. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:IT-Solid oxide fuel cell;Dual oxide cathode;(La,Sr)CoO3/(La,Sr)(2)CoO4;Cathode performance;Electrochemical impedance;spectroscopy