Preparation and characterization of lithium ion conducting Li2S-P2S5-GeS2 glasses and glass-ceramics

• Published in: Journal of non-crystalline solids Vol. 356; no. 44-49; pp. 2666 - 2669
• Main Authors: MINAMI, Keiichi, HAYASHI, Akitoshi, TATSUMISAGO, Masahiro
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Elsevier 01.10.2010
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystallinity; Crystals; Diffusion in solids; Exact sciences and technology; Germanium; Glass; Glass ceramics; Glasses (including metallic glasses); Ion concentration; Lithium; Materials science; Materials synthesis; materials processing; Mechanical milling; Physics; Precipitation; Self-diffusion and ionic conduction in nonmetals; Specific materials; Theory of diffusion and ionic conduction in solids; Transport properties of condensed matter (nonelectronic); Phosphates; Electrical conductivity; Ionic conductivity; Glass; Solid electrolyte; Crystallinity; XRD; Mechanical alloying; Precipitation; Glass-ceramic; Lithium ion conductivity; Mechanochemical synthesis; Germanium; Solid electrolytes; Mechanochemistry
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2010.05.016

Glasses and glass-ceramics in the system Li2S-P2S5-GeS2 with the following three compositions of Li7+ x P3a degree x Ge x S11, Li7P3a degree y GeyS11 a degree y/2, and (100a degree z)(70Li2SA.30P2S5)A.zGeS2, were prepared by using a mechanical milling technique. At the compositions of Li7+ x P3a degree x Ge x S11 and Li7P3a degree y Ge y S11 a degree y/2, conductivity decreased monotonically with an increase in x or y. The conductivity decrease was due to the increase of lithium ion concentration around ortho thio-phosphate which led to the precipitation of the Li3.2P0.96S4 crystal. At the composition of (100a degree z)(70Li2SA.30P2S5)A.zGeS2, conductivity was enhanced with an increase in z (up to z =2), and the glass-ceramic with 2mol% of GeS2 showed the highest conductivity of 5.4A plus or minus 0.1A-10a degree 3 Scma degree 1 at room temperature. From the XRD pattern, germanium would not be incorporated into the Li7P3S11 crystal. One possible reason for the conductivity enhancement is the increase of the crystallinity of Li7P3S11 crystal.