Extrusion process for the manufacture of beta"-alumina solid electrolyte tubes

For future stationary energy storage requirements, sodium batteries are potentially suitable candidates owing to their high energy density, proven reliability, high faradaic efficiency and the use of abundant low-cost raw materials. Tubular battery designs require a thin-walled solid electrolyte tube, usually formed from ion-conductive beta″-alumina ceramic. State-of-the-art manufacturing methods, namely isostatic pressing and electrophoretic deposition, contribute a significant proportion of battery cost, and it is desirable to identify a high-volume low-cost process for the ceramic. Extrusion offers the potential for a rapid low-cost, high-volume production process but requires special development for adaptation to the demands of solid electrolyte production. This paper summarizes recent trials on extrusion as a process for producing beta″-alumina ceramic electrolyte tubes.