Preparation of amorphous solid electrolytes in the system Li 2S–SiS 2–Li 4SiO 4 by mechanical milling

Abstract

Amorphous solid electrolytes in the system Li 2S–SiS 2–Li 4SiO 4 were successfully prepared from a mixture of Li 2S, SiS 2 and Li 4SiO 4 crystals using a mechanical milling technique at room temperature. In the composition range 0≤ x≤5 of (100− x)(0.6Li 2S·0.4SiS 2)· xLi 4SiO 4, conductivities of the oxysulfide powders mechanically milled for 20 h were as high as 10 −4 S cm −1 at room temperature, which are comparable to the values of the corresponding composition of melt-quenched glasses. As the period of mechanical milling treatment was increased from 0 to 20 h, the structure of milled powders became similar to that of the glasses prepared by melt quenching. Such a structure change brought about a large conductivity increase in the resultant powders from 10 −9 to 10 −4 S cm −1.