Electrical properties of new glasses based on the Li2S-SiS2 system

Improvement of large energy density systems such as lithium ion batteries r equires an understanding of the electrode materials and identification of n ew electrolytes. For safety reasons, solid sate electrolytes are preferred. This study is based on past results on the Li2S-SiS2 system. AC impedance spectroscopy was used to determine the ionic conductivity of glasses where additions were made of sulfides and oxides of groups TVA, VA, VB or VIA to the base glass composition 60/40 Li2S-SiS2 (mol%). These additions improved the stability of these glasses, so much so that thick samples (> 2 mm) cou ld be prepared by cooling without quenching. Addition of lithium halides fu rther increased conductivity. Ionic conductivities > 2 x 10(-3) S/cm at roo m temperature were measured, amongst the largest reported in the glass lite rature for lithium electrolytes. The conductivity activation energy of thes e glasses will be reported. (C) 1999 Elsevier Science B.V. All rights reser ved.