Mechanochemical synthesis of amorphous solid electrolytes using SiS2 and various lithium compounds

Lithium ion conducting amorphous solid electrolytes were prepared from SiS2 and various kinds of lithium compounds by mechanical milling. Electrolytes using Li2S, Li3N, and Li2O as a lithium source exhibited high conductivities of 10−5–10−4 S cm−1 at room temperature, while those using Li3PO4, LiOH, and LiCl showed conductivities lower than 10−6 S cm−1. The conductivity of the 50Li2O·50SiS2 (mol%) solid electrolyte drastically increased with the milling period from 0 to 5 h. The enhancement of conductivity during milling is due to the formation of the corner-shared and isolated SiS4 and SiOS3 tetrahedral units in the solid electrolyte.