Impact of Spark Plasma Sintering Conditions on Ionic Conductivity in La_1.95Sr_0.05Zr₂O_7-δ Electrolyte Material for Intermediate Temperature SOFCs

Abstract

To overcome the ageing issues of the solid oxide fuel cells (SOFCs), the proton ceramic fuel cells (PCFCs, also called intermediate temperature SOFCs) were developed, which operate at intermediate temperatures (400°-600°C). In this paper, we present the synthesis of Sr-doped lanthanum zirconate pyrochlores La 1.95 Sr 0.05 Zr 2 O 7-δ (LSZO) that can be used as electrolyte materials. Conductivity measurements of LSZO were performed in dry and wet (5% H 2 O) atmospheres using electrochemical impedance spectroscopy. As the sintering processes have the potential to affect not only the bulk conductivity but also the response of grain boundaries, five samples prepared under various SPS conditions were studied.

Fluorite-based proton conducting oxides: structures, materials and applications

“…78 Huo et al found that the Sr doping limit was x = 0.025 by using an oxalic acid co-precipitation method and sintering at 1500 °C. 79 Antonova et al reported a higher Sr doping limit of x = 0.035 when the sintering was performed at 1600 °C on the samples prepared with a citrate–nitrate method. 80 These results clearly indicate that by using the method to synthesize the materials with smaller grain size and sintering at higher temperature, the solubility of Sr in La 2 Zr 2 O 7 is improved.…”