Exceptional High‐Performance Oxygen Transport Membrane and Comprehensive Study on Mass/Charge Transport Properties

This study focuses on mixed‐conducting perovskite membranes for efficient oxygen supply, aiming to replace energy‐intensive cryogenic distillation with a more practical alternative. A La and Nb co‐doped BaCoO 3− δ perovskite is introduced, Ba 0.95 La 0.05 Co 0.8 Fe 0.12 Nb 0.08 O 3− δ (BLCFN) with a record‐breaking oxygen permeation flux, surpassing all known single‐phase perovskite membranes. To elucidate its superior membrane performance, the mass/charge transport properties and equilibrium bulk properties are investigated and quantitative indicators ( D O = 5.8 × 10 −6 cm 2 s −1 , k O = 1.0 × 10 −4 cm s −1 , σ ion = 0.93 S cm −1 at 900 °C) reveal fast diffusion and excellent surface gas‐exchange kinetics. The oxygen permeability of 12.4 mL cm −2 min −1 and over 200 h of long‐term stability is achieved in an air/He atmosphere at 900 °C. By presenting a material that demonstrates higher performance than Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3− δ (BSCF), currently known for its highest permeability, it is believed that this marks a significant step toward innovative performance enhancement of perovskite oxide‐based membranes.