Performance of La0.75Sr0.25Cr0.5Mn0.5O3−δ perovskite-structure anode material at lanthanum gallate electrolyte for IT-SOFC running on ethanol fuel

Perovskite-structure La_0.75Sr_0.25Cr_0.5Mn_0.5O_3−δ (LSCM) powders were prepared using a simple combustion process. Thermal analysis was carried out on the perovskite precursor to investigate the oxide-phase formation. The structural phase of the powders was determined by X-ray diffraction. These results showed that the decomposition of the precursors occurs in a two-step reaction and temperatures higher than 1100 °C are required for these decomposition reactions. For the electrochemical characterization, LSCM anode materials and (Pr_0.7Ca_0.3)_0.9MnO₃ (PCM) cathode materials were screen-printed on two sides of dense La_0.8Sr_0.2Ga_0.8Mg_0.2O₃ (LSGM) electrolyte layers prepared by tape casting with a thickness of about 600 μm, respectively. The morphology of the screen-printed La_0.75Sr_0.25Cr_0.5Mn_0.5O_3−δ perovskite thick films (65 μm) was investigated by field emission scanning electron microscope and showed a porous microstructure. In addition, fuel cell tests were carried out using humidified hydrogen or ethanol stream as fuel and oxygen as oxidant. The performance of the conventional electrolyte-supported cell LSCM/LSGM/PCM while operating on humidified hydrogen was modest with a maximum power density of 165, 99 and 62 mW cm⁻² at 850, 800 and 750 °C, respectively, the corresponding values for the cell while operating on ethanol stream was 160, 101 and 58 mW cm⁻², respectively. Cell stability tests indicate no significant degradation in performance has been observed after 60 h of cell testing when LSCM anode was exposed to ethanol steam at 750 °C, suggesting that carbon deposition was limited during cell operation.