Synthesis and doping effects in highly conductive chalcogenide solid electrolytes.

Lithium and sodium ion batteries have been a vital component in the growth of small, portable electronic devices and EVs over the past 30 years. For future energy needs, changes to battery chemistry and composition will be necessary for two primary reasons: safer and higher energy batteries. Metal anodes have not seen widespread commercialization because of their propensity to react aggressively with the flammable liquid electrolytes commonly used in modern batteries. Non-flammable solid-state batteries (SSB) with solid electrolytes can safely be used with metal anodes, potentially providing a solution to both problems. The future perspective of safer battery is that adopting the solid electrolytes in place in liquid electrolytes. Solid electrolytes are well-known with their nonvolatile and nonflammable and safely cooperation with metal anode. Chalcogenide sulfide solid electrolytes such as Na3SbS4 family are noted for their air stability, however, indicates several hardships including poor electrochemical stability, time and energy consuming synthesis processes, and need to be improved its ionic conductivity. This dissertation pursues to overcome to address each of these challenges through doping and synthesis strategies. In this work, novel synthesis approaches of Na3SbS4, different dopant and doping strategies are examined. The new synthesis techniques shorten the time and provide considerable energy efficiency. The new dopants not just only increase the ionic conductivity, but also enhances the electrochemical stability at the interface towards Na metal. These advancements drive progress in chalcogenide sulfide solid electrolyte research and set the stage for the widespread adoption of next-generation sodium metal batteries.