Lanthanum strontium manganese chromite cathode and anode synthesized by gel-casting for solid oxidefuel cells

Abstract

Lanthanum strontium manganese chromite, (La_0.75Sr_0.25)Cr_0.5Mn_0.5O₃ (LSCM), perovskite oxides were synthesized by gel-casting and solid-state reaction techniques as electrode materials of solid oxide fuel cells (SOFCs). Thermal and XRD analyses indicate that the phase formation temperature of LSCM powders synthesized by the gel-casting technique is 50–100 °C lower than that by the solid-state reaction method. The LSCM/YSZ composite electrode prepared using the gel-casting LSCM powder is shown to have a much higher electrochemical activity for the O₂ reduction and H₂ oxidation reactions than that using the solid-state reaction powder. The reason for this is most likely related to the homogeneously distributed and immobilized precursor particles in a polymeric network, forming micro-scale interconnected networks. The results in the present study demonstrate the advantages of the aqueous gel-casting method in the synthesis of high quality and highly catalytic active LSCM oxide powders for SOFCs. Finally, a novel symmetric LSCM/YSZ composite anode and LSCM/YSZ composite cathode-supported thin-electrolyte cell is fabricated and demonstrated.