Versatile Wet-Chemical Synthesis of Sulfide Solid Electrolytes Using Cosolvents for All-Solid-State Batteries

Rechargeable lithium-ion batteries (LIBs) have been widely used for portable electronic devices, electric vehicles, and energy storage systems. Since LIBs have serious safety issues originating from the use of flammable liquid electrolytes, all-solid-state batteries (ASSBs) are in the spotlight as the next-generation system. Especially, ASSBs employing sulfide solid electrolytes (SEs) show promising performances owing to the excellent deformability and high ionic conductivity of sulfide SEs. Recently, wet-chemical synthesis of sulfide SEs has attracted much attention in the viewpoint of scalable production. Thus far, most wet-syntheses using SE precursors proceeded in a suspension using various organic solvents, such as tetrahydrofuran and acetonitrile, and corresponding products have been restricted to binary Li₂S-P₂S₅ composition.<br/>In this presentation, we report a new wet-synthesis of sulfide SEs (Li₆PS₅Cl , Li₁₀GeP₂S₁₂, and Na₁₁Sn₂PS₁₂ ) using co-solvents of ethylenediamine and 1,2-ethanedithiol, which proceeds in a homogeneous solution. The applicability of the wet-synthesized SEs is also presented.<br/> <br/>[1] <i>Adv. Energy Mater</i>. <b>2018</b>, <i>8</i>, 1800035.