Electrolyte Design and Challenges in Lithium-Sulfur Batteries

There is a wide discussion about lithium-sulfur batteries concerning electrolytes due to their potential ability to exceed the traditional circumstances of energy density in lithium-ion systems. However, the commercialization of this system is facing crucial challenges currently because of the insulting nature and the volume expansion of sulfur, roughly about 76%, the movement of polysulfides between the two electrodes, and the insufficient surface qualities of the lithium metal anode with non-aqueous lithium electrolytes [1]. The electrolyte here becomes a very influential factor in all active compositions that work in lithium polysulfides and lithium, primarily functioning on safety and lifespan. This review article unravels the electrolyte design for lithium-sulfur batteries in recent literature and research, focusing on liquid, solid-state, and quasi-solid systems. Also, a special insight looks into electrolyte composites, additives, and concentrates due to the shuttle effect, interfacial stability, and ionic conductivity. Many studies today have approached promising strategies and ongoing limitations in the field, as well as some potential solutions, helping the electrolyte system maintain high energy density and long-term stability.