Intermediate temperature solid oxide electrolysis cell using LaGaO3-base oxide

NiFe oxide composite was studied as cathode of steam electrolysis cell using LaGaO3 based oxide for electrolyte and it was found that H2 formation rate at 1.6 V was much improved by combination of oxygen ion conducting oxide with NiFe (9:1) bimetallic alloy. In particular, a combination with La0.6Sr0.4Fe0.9Mn0.1O3 (LSFM) or Ce0.8Sm0.2O2 (SDC) is highly effective for increasing current density. Impedance plots for cathode consisted of two semicircles, which could be assigned to a diffusion and an activation overpotential in low and high frequency region, respectively. Compared with NiFe, mixing with SDC is much more effective for decreasing the diffusion overpotential. This might be assigned to increase in three phase boundary and porosity of cathode.