Study of Ga Doped LSCM as an Anode for SOFC

A phase pure La0.75Sr0.25Cr0.4Ga0.1Mn0.5O3 (LSCGM) was synthesized by the solid state reaction method. LSCGM crystallized with rhombohedral symmetry in the space group R-3c. AC impedance measurements using symmetrical cell arrangement showed that the area specific resistance (ASR) was 0.69 Omega cm(2) at 850 degrees C in wet 5% H-2. A three-electrode arrangement with thick electrolyte was used to study the anodic characterization in isolation at various temperatures in wet hydrogen (97 vol% H-2 and 3vol% H2O) and methane (97 vol% CH4 and 3 vol% H2O) over a period of 100 hr. For H-2, the open circuit voltage (OCV) was found to decrease with temperature, whereas a different trend was observed in CH4. The value of anodic polarization (RP) at similar to 868 degrees C was found to be 0.65 Omega cm(2) and 2.0 Omega cm(2) in wet hydrogen and methane respectively. At 900 degrees C, the corresponding values were 0.45 and 1.65 Omega cm(2) respectively. The microstructural study revealed a good LSCMG - YSZ interface even after 100 hr of operation.