Novel glass-ceramic solid electrolytes in this ternary system were prepared from mechanically milled powders. With increasing heat-treatment temperature, the room-temperature conductivity of the glass-ceramics attained 1.2 x 10–3S/cm. This was higher than the maximum conductivity of solid solutions in the system, Li4SiS4-Li3PS4. An enhancement in conductivity by heat-treatment above the crystallization temperature was attributed to the formation of a highly conductive crystalline phase having the same superlattice structure as the thio-LISICON phase of Li4–xGe1–xPxS4 (0.6 < x < 0.8). This exhibited conductivities of greater than 10–3S/cm at room temperature.

Fast Lithium-Ion Conducting Glass-Ceramics in the System Li2S-SiS2-P2S5. A.Hayashi, Y.Ishikawa, S.Hama, T.Minami, M.Tatsumisago: Electrochemical and Solid-State Letters, 2003, 6[3], A47-9