Preparation and characterization of lithium ion-conducting glass-ceramics in the Li1+xCrxGe2-x(PO4)3 system

Li2O-Cr2O3-GeO2-P2O5 based glasses were synthesized by a conventional melt-quenching method and successfully converted into glass-ceramics through heat treatment. Experimental results of DTA, XRD, ac impedance techniques and FESEM indicated that Li1.4Cr0.4Ge1.6(PO4)(3) glass-ceramics treated at 900 degreesC for 12 h in the Li1+xCrxGe2-x(PO4)(3) (x = 0-0.8) system exhibited the best glass stability against crystallization and the highest ambient conductivity value of 6.81 x 10(-4) S/cm with an activation energy as low as 26.9 kJ/mol. In addition, the Li1.4Cr0.4Ge1.6(PO4)(3) glass-ceramics displayed good chemical stability against lithium metal at room temperature. The good thermal and chemical stability, excellent conducting property, easy preparation and low cost make it promising to be used as solid-state electrolytes for all-solid-state lithium batteries. (C) 2004 Elsevier B.V. All rights reserved.