Behavior of strontium- and magnesium-doped gallate electrolyte in direct carbon solid oxide fuel cells

Abstract

Perovskite-type La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) is synthesized by conventional solid state reaction. Its phase composition, microstructure, relative density, and oxygen-ionic conductivity are investigated. Tubular electrolyte-supported solid oxide fuel cells (SOFCs) are prepared with the LSGM as electrolyte and gadolinia doped ceria (GDC) mixed with silver as anode. The SOFCs are operated with Fe-loaded activated carbon as fuel and ambient air as oxidant. A typical single cell gives a maximum power density of 383mWcm−2 at 850°C, which is nearly 1.3times higher than that of the similar cell with YSZ as electrolyte. A stability test of 72min is carried out at a constant current density of 210mAcm−2, with a fuel utilization of 60%, indicating that LaGaO3-based electrolyte is promising to be applied in direct carbon SOFCs (DC-SOFCs).