Comparative performance assessment of nano-composite cathode of LMSO-BSCMF for low temperature solid oxide fuel cell applications

Abstract

The development of novel cathode materials for low temperature solid oxide fuel cell (SOFC) applications is one of the significant research areas in materials engineering. In the current work, composite cathode materials were prepared by two different modes and the fuel cell performance was assessed using a gadolinium-doped ceria (GDC) electrolyte. Nanocomposite cathodes were fabricated using a lanthanum strontium manganite oxide (LSMO) powder of a 50-100 nm particle size and Ba0.5Sr0.5(Co0.2Mg0.8)0.2Fe0.8O3 (BSCMF) powder of a 1 µm particle size. The cathodes were prepared as layered composites and mixed composites. The electrochemical performance of the symmetric cells was investigated by electrochemical impedance spectroscopy (EIS) at the intermediate temperature of 700°C using air atmosphere. The cathode film coating on the electrolyte was sintered at three different temperatures (900, 950 and 1000°C) and the cell performance was assessed at 700°C. Lower polarization resistance (RP) values were recorded for the cell produced at 900°C. The RP of the nano-composite cathodes was measured as lower (2.72 Ω-cm 2 for the layered composites and 1.76 Ω-cm 2 for the mixed composites) compared with LSMO. Hence, the results demonstrate the potential of using an LSMO-BSCMF composite in the mixed mode as a cathode for low temperature SOFCs to achieve a lower polarization potential.