A Novel Solid Electrolyte Material LiNaSO_4-Al_2O_3 for Intermediate Temperature Fuel Cells

Three-phase composite ceramic electrolyte was prepared and studied. The XRD pattern ofthis material shows a composited phase structurd of LiNaSO4 and γ-Al2O3. High conductivety(10-2 to 10-1 S/cm) can be achieved at 500℃. A phase transition appears at about 499℃. It maybe caused by an existence of bbc phase. Al2O3 makes a good LiNaSO4-Al2O3 skeleton at hightemperature, and the conductivity enhanced. The proton transport number for high temperaturephase is 0.9~1.0.