Sulfide Solid Electrolytes Li2S+SiS2+Al2S3 | Li2S+SiS2+Al2S3  Chemical batteries play an important role in energy storage and conversion, Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. However, traditional lithium-ion batteries usually use organic liquid electrolytes with relatively high ionic conductivity, but there are many disadvantages such as the risk of inflammable and explosive, short life and low energy density. Compared with the lithium-ion battery with liquid electrolyte, All-solid-state lithium battery with non combustible solid electrolyte can avoid these problems, meanwhile the solid electrolyte can also effectively inhibit the formation of lithium dendrite, thus improving the service life of the battery. Among which sulfide-based solid electrolytes have become more widespread and attracted significant attention because they possess high conductivities and good mechanical properties for the formation of effective interfaces between solids.

The most typical sulfide crystalline solid electrolyte is thio-LISICON, a lithium superionic conductor, the new crystalline material family found in the Li ₂S-GeS₂-P₂S₅ system, the general chemical formula is Li4-xA1-xBxS4 (A=Ge, Si…, B= P, Al, Zn…), which demonstrates the highest lithium-ion conductivity of 2.2 × 10^-3s cm^-1 at room temperature, together with negligible electronic conductivity, high electrochemical stability. Solid electrolyte materials Li₂S+SiS₂+ Al₂S₃ and Li₂S+SiS₂+ Al₂S₃, a novel and promising solid electrolytes, prepared by a high-energy ball-milling process or by a conventional melt-quenching method act as both an ionic conductor and a separating membrane in all-solid-state rechargeable lithium batteries, which have high ionic conductivity, negligible electronic conductivity, wide operating voltage window and good chemical compatibility with the electrode.