Influence of Y and Gd Doping on La2Ti2O7 Layered Perovskite for Solid Oxide Fuel Cell Applications

Layered perovskite oxides exhibit significant potential as an electrolyte for moderate-temperature solid-oxide fuel cells (SOFCs) owing to their structural flexibility and ionic transport properties. The study aims to examine the impact of rare-earth element incorporation on the structural, microstructural, and electrical characteristics of the material La2Ti2O7. The layered perovskite was doped with Y3+ and Gd3+ ions using a conventional solid-state method, followed by thermal sintering at elevated temperatures. Physicochemical characterizations were carried out to examine the structural and morphological properties. Impedance measurements carried out over the temperature range 300–750 °C confirmed improved electrical conductivity in doped samples, and the contributions came from both grain and grain boundary conduction paths. The oxygen vacancy formation and structural changes due to Y and Gd doping improved ionic transport properties. These studies confirmed that rare-earth-doped La2Ti2O7 perovskites are potential materials for improved electrolytes in intermediate-temperature SOFCs.