Fabrication and testing of beta"-alumina electrolyte assemblies

Process development has been carried out to enhance the properties of β"-Al₂O₃ electrolytes manufactured in-home by the electrophoretic deposition (EPD) process. This development included solid-state and resin synthesis routes. Alternate α-Al ₂O₃ precursors and calcining temperatures were evaluated for the solid-state synthesis process. Sintered electrolyte specimens were characterized for chemical and phase composition and for strength. In addition, electrical resistivity determinations were made over the temperature range of 250 to 400°C using complex plane AC impedance analysis. Electrolyte assemblies of 40 Ah capacity were fabricated by sealing the EPD β"-Al₂O₃ tubes to α-Al₂O₃ headers. Electrolyte assemblies have been tested in Na/S cells at current densities to 373 mA/cm²