High lithium conductivity in Li1.3Cr0.3Ge1.7(PO4)3 glass-ceramics

A Li2O-Cr2O3-GeO2-P2O5 glass was prepared and converted into glass-ceramics through treating at approximately 800-1000 degreesC for 12 h. X-ray diffraction (XRD) analysis indicated that the phase present in the glass-ceramics was LiGe2(PO4)(3)-type structure in which Ge4+ ions were partially replaced by Cr3+ ions. The lithium ion conductivity of the glass-ceramics increased with the growth of the phase, and the highest value of 5.7 x 10(-4) S/cm with an activation energy as low as 27.8 KJ/mol was obtained at room temperature for the specimen treated at 850 degreesC for 12 h. The high conductivity, good chemical stability and easy fabrication of Li1+xCrxGe2-x(PO4)(3) system suggest they are promising solid electrolytes for all-solid-state Li-ion rechargeable batteries. (C) 2004 Elsevier B.V. All rights reserved.