Improvement in anodic activity of Ni by Fe addition for intermediate temperature SOFC using LaGaO₃ electrolyte

Effects of various additives to Ni anode on SOFC using La _0.9Sr_0.1Ga_0.8Mg_0.2O₃ based oxide electrolyte were investigated in this study for increasing the surface activity. Among the examined additives, it was found that the addition of small amount of Fe is highly effective for increasing the anodic activity. When 5 wt% Fe was added to Ni anode, the anodic overpotential was as small as 34 mV at 873 K, 0.1 A/cm2, which is almost half of pure Ni anode. Since the estimated activation energy for anodic reaction decreased, addition of Fe to Ni seems to be effective for increasing the activity of Ni for anodic reaction. XRD measurement after power generation measurement suggests that added Fe formed alloy with Ni. Addition of third element to Ni-Fe bimetallic anode was also studied and it was found that addition of small amount of Pt is effective for further increasing the activity of Ni anode. Consequently, this study reveals that Ni-Fe-Pt is highly active for anodic reaction of SOFCs at decreased temperatures.