Mechanochemical synthesis of Li2S–P2S5 glass electrolytes with lithium salts

Lithium salt incorporated glasses in the systems Li2S–P2S5–LiX (X = I, BF4, TFSA, Tf, and PF6) were prepared by mechanical milling. The conductivity of obtained glasses largely depended on the variety of lithium salts. Conductivity of the glass was enhanced by incorporating LiI because of dissociation of LiI in the glass matrix. In the case of incorporating LiTFSA, LiTf and LiBF4, the conductivities of the glasses were decreased with an increase in the salt content. It was due to the difficulty of dissociating the lithium salt because there were few free ions in the glass. Conductivity of LiPF6-incorporated glass was largely decreased because of the formation of highly resistive compound by the reaction between LiPF6 and sulfide glass during the milling treatment.