Dual-Phase MIEC Membranes

In this chapter, the critical factors affecting oxygen permeation through dual-phase membranes are discussed with a view to improving the permeability of dual-phase membranes. Based on the current knowledge in solid-state electrochemistry, two series of dual-phase membranes, made of ceria-based ionic conductors and Fe-based perovskite mixed conductors, are suggested as promising dual-phase materials. Oxygen exchange on the membrane surface, preparation methods, sintering temperature, and phase composition are all critical factors to affect the membrane performance and discussed with experiment demonstration. Other factors, such as the elemental composition of the phases, grain size, grain size ratio between the two phases, the conductivity of the mixed conducting phase, the microstructure, and thickness, all affect the oxygen transport process and deserve thorough investigation.