Solid State Electrochemical Oxygen Separation and Compression

Ceramic and solid-state electrochemical oxygen separation and compression systems offer the ease of producing high purity and high pressure oxygen from a variety of gaseous streams representative of ambient and constrained system exposure conditions (terrestrial and space). The electrochemical cells utilize exclusive oxygen ion conducting ceramic membranes (doped fluorites) and operate in a 550-850 °C temperature range. Advanced perovskites synthesized from non-noble and non-strategic materials serve as electrodes for both oxygen reduction and evolution. A number of electrochemical cells, connected in series using dense, electronically-conducting perovskite interconnects form the basis of a “cell stack” for increased oxygen production. The robust solid-state device provides a means of oxygen separation/compression, operating favorably in environments without reducing atmospheres (unlike terrestrial fuel/electrolysis cells). Thermochemical-electrochemical principles for oxygen separation and compression will be discussed. Materials for the construction of cells and stack along with fabrication techniques will be examined and the basis for material selection will be described. Approaches for the electrochemical performance improvement will also be discussed.