Abstract
Lithium ion conductors, Li3-2x(In1-xMx)2(PO4)3 (M=Ti, Zr; x=0.1,0.15,0.2), were synthesized by a solid state reaction under four different sintering conditions. The solid electrolyte thin films were prepared by r-f sputtering. In order to measure the ionic conductivity, the A. C. impedance method was used to investigate the response under a range of frequencies, equivalent circuit to fit the impedance graphs was desired. . In general, the ionic conductivity of Li3-2x(In1-xTix)2(PO4)3 is higher than that of Li3-2x(In1-xZrx)2(PO4)3 . It is also found that the ionic conductivity of Li3-2x(In1-xTix)2(PO4)3 sintered under N2 atmosphere is higher than that sintered under O2; on the other hand, the Li3-2x(In1-xZrx)2(PO4)3 samples sintered under O2 exhibit higher ionic conductivities. The highest ionic conductivity at room temperature was 9.39×10-5(S/cm) for Li2.8(In0.9Ti0.1)2(PO4)3 sintered under N2 atmosphere and at 800℃ for 6 hours. The highest ionic conductivity of solid electrolyte thin film at room temperature is 8.0×10-5(S/cm) for Li2.7(In0.85Ti0.15)2(PO4)3 prepared under a mixture of 40% O2and 60% Ar atmosphere with the bass pressure is 3.0×10-2.