Novel structured Sm0.5Sr0.5CoO3-δ cathode for intermediate and low temperature solid oxide fuel cells

The performance of solid oxide fuel cell (SOFC) can be significantly enhanced using nanostructured cathode obtained by infiltration/impregnation method. However, this method has been limited due to multi-step preparation process and instability of the obtained nanoscale catalyst under long-term operation. We report here a simple, cost-effective and reproducible approach to fabricate nanostructured Sm0.5Sr0.5CoO3-delta (SSC) cathode with enhanced performance and stability. The SSC powders were prepared by a freeze-drying method through a combustion route using Pluronic F-127 as the template. The SSC freeze-drying powders have unique morphology and a significant phase change at 750 degrees C. The oxygen non-stoichiometry (delta) of the SSC powders is 0.18 at room temperature, while the delta values are 0.66, 0.75 and 0.90 at 600 degrees C, 700 degrees C and 800 degrees C, respectively. The novel structured SSC cathode was prepared by screen-printing and one-step sintering process using the freeze-drying SSC powders. Maximum cell power densities of 0.83 and 1.13 W cm(-2) are achieved at 550 degrees C and 600 degrees C, respectively for single cells with the novel structured SSC cathode. Moreover, single cells show excellent stability at 600 degrees C under a current density of 600 mA cm(-2) over 250 h. This work expands opportunities to exploit nanotechnology in a wide range of intermediate and low temperature energy conversion devices. (C) 2020 Elsevier Ltd. All rights reserved.