Structure and properties of the 70Li2S•(30-x)P2S5 • xP2O5 oxysulfide glasses and glass-ceramics

The 70Li(2)S center dot (30 - x) P2S5 center dot xP(2)O(5) (mol%) oxysulfide glasses were prepared by the melt quenching method. The glasses were prepared in the composition range 0 <= x <= 10. The glass-ceramics were prepared by heating the glasses over crystallization temperatures. The POnS3-n (n = 1-3) oxysulfide units were produced in the glasses and glass-ceramics by partial substituting P2O5 for P2S5. In particular, the P2OS64- unit would be produced by substituting a small amount of P2O5 for P2S5. The oxygen atoms were incorporated into the Li7P3S11 crystal structure because the diffraction peaks of the oxysulfide glass-ceramic shifted to the higher angle side. The glass-ceramic with 3 mol% of P2O5 exhibited the highest conductivity of 3.0 x 10(-3) S cm(-1) and the lowest activation energy for conduction of 16 kJ mol(-1). The P2OS64- dimer units in the oxygen-incorporated Li7P3S11 crystal would improve conductive behavior of the Li2S-P2S5 glass-ceramics. (C) 2007 Published by Elsevier B.V.