Entropic stabilization enhanced ionic transport in (La, Nd, Sm, Gd)AlO₃ perovskite electrolytes

The introduction of entropy-stabilized oxides (ESOs) marks a significant shift in the design of perovskite electrolytes by utilizing compositional disorder to enhance ionic transport properties. In this study, we present a novel formulation of (La_0.25Nd_0.25Sm_0.25Gd_0.25)AlO₃, a multi-cation perovskite oxide through entropy stabilization. Its ionic conductivity exceeds 0.23 S/cm at 500 °C, which is substantially higher than that of pristine LaAlO₃. Through combined computational and experimental analyses, we demonstrate that entropy-induced band narrowing, surface band bending, and local electric field effects enable a new ion transport mechanism, which differs from traditional defect pathways created by doping. These findings represent a conceptual breakthrough in material design for intermediate-temperature solid oxide fuel cells (SOFCs) and proton-conducting fuel cells (PCFCs), advancing the field of electrochemical energy devices.