1. Molecular formula: Li₂S; Molecular weight: 45.95 g/mol

2. Appearance: White / off-white crystalline powder; high-purity grade is colorless and transparent crystal

3. Melting point: 938 ℃

4. Density: 1.75 g/cm³

5. Solubility: Soluble in water (violent hydrolysis), soluble in ethanol; insoluble in diethyl ether and hydrocarbon solvents

6. Crystal structure: Antifluorite cubic crystal system

1. Synthesis of sulfide solid electrolytes for the preparation of high ionic conductivity sulfide solid electrolytes used in all-solid-state lithium batteries.

2. As a cathode material for lithium-sulfur batteries, it is directly used as the cathode active material for solid-state lithium-sulfur batteries, featuring high theoretical capacity and energy density far exceeding those of traditional lithium-ion batteries.

3. As a lithium-supplementing additive for lithium-ion batteries, it acts as an anode/cathode prelithiation agent to compensate for the initial irreversible capacity loss of silicon-carbon anodes and high-nickel cathodes, improving the overall capacity and cycle life of the battery.

4. Synthesis of high-purity organolithium and inorganic lithium salts for the preparation of high-purity alkyl lithium, lithium thio salts, etc., applied in the fields of medicine, lithium battery electrolytes, and specialty chemicals.