THE THERMAL DECOMPOSITION OF SODIUM BETA'-ALUMINA SOLID ELECTROLYTE CERAMIC

摘要

Sodium beta"-alumina is one of the best characterized solid electrolytes, but its high temperature chemistry in the range 700K to 1800K is only partly understood. In particular, the kinetics of slow degradation reactions of sodium beta"-alumina have not been definitively characterized. We have begun investigation of high temperature processes in the range 1000K to 1500K which may lead to degradation of sodium beta"-alumina in alkali metal thermal to electric converter (AMTEC) devices. AMTECs are under development as power sources for future outer planetary robotic space missions, where they must operate for very long times. Mission duration and high temperature operation of AMTECs, to perhaps 1250K, have driven the need to investigate potential degradation reactions at even higher temperatures to greatly accelerate testing.