Mechanochemical synthesis of lithium ion conducting glasses and glass-ceramics in the system Li2S-P-S

The Li2S-P-S glasses were prepared by mechanical milling from the mixture of Li2S and elemental phosphorus and sulfur. The conductivity of the glasses was 2.0 x 10(-5) S cm(-1) at room temperature. Raman spectroscopy revealed that the glasses mainly consisted of PS43- and Li+ ions, and partially contained homo bonds such as P-P and S-S bonds. Heat treatment of the glasses above the crystallization temperature produced glass-ceramics in which the crystal analogous to thio-LISICON with high conductivity was precipitated. The precipitation of the thio-LISICON analog enhanced the conductivity of the glasses, and the conductivity of the glass-ceramics was 3.9 x 10(-4) S cm(-1) at room temperature. The Li2S-P-S glass-ceramics contained mainly 4 ions with a small amount of S-S bonds, and the amounts of the P-P and S-S homo bonds in the glass-ceramics were diminished by heat treatment than those in the glasses. The local structure of the Li2S-P-S glass-ceramics was similar to that of the Li2S-P2S5 glass-ceramics prepared from Li2S and P2S5 using as raw materials. (c) 2005 Elsevier B.V. All rights reserved.