It is typically reacted with network-forming sulfides (like P2S5, SiS2, GeS2) and lithium halides via three main pathways: (1) High-Energy Ball Milling (Mechanochemical Synthesis): Precursors are milled in an inert atmosphere (Argon, <1 ppm O2/H2O) with a ball-to-powder ratio between 20:1 and 40:1 for 20–40 hours, which amorphizes the mixture into a sulfide glass phase. For many systems, this is followed by a post-annealing step at 200°C–550°C to precipitate highly conductive crystalline or glass-ceramic phases (e.g., Argyrodite or Li7P3S11). (2) Solid-State Sintering: Stoichiometric mixtures of Li2S, P2S5, and modifiers are sealed under vacuum in quartz ampoules and heated directly to temperatures ranging from 500°C to 900°C (or up to 1100°C for melt-quenching systems like Li2S–SiS2). High crystallinity, though grain boundary engineering is required during subsequent processing to ensure seamless interparticle contact. (3) Liquid-Phase/Solution Synthesis: Dissolving Li2S and co-precursors in anhydrous organic solvents such as tetrahydrofuran (THF), acetonitrile, or ethanol. The reaction proceeds at moderate temperatures (25°C–80°C), followed by vacuum drying and calcination. It enables low-temperature scalable wet-chemical processing, slurry casting, and excellent infiltration into porous, tortuous cathode frameworks.