Lithium-Sulfur Batteries are a promising future battery technology due to their characteristics, including high theoretical specific capacities of up to 1670 Ah/kg and gravimetric energy densities of 2600 Wh/kg [1]. These values surpass those of conventional lithium-ion batteries. Moreover, sulfur, a key component in Li-S batteries, is abundant and environmentally benign compared to materials commonly used in lithium-ion batteries.

However, challenges persist in achieving stable performance. The shuttle current phenomenon remains a significant hurdle, undermining battery stability. Additionally, complexities in polysulfide analysis hinder a comprehensive understanding of the battery mechanism. Since the main reactions of these batteries, as well as the shuttle current reaction, all take place in solution, the choice of electrolyte significantly influences battery processes, affecting both capacity and stability [4].

In this work, investigations into the potential of Lithium as an indicator of solvent polarity and Sulfur potentials have shed some light on these effects. Cyclic voltammetry studies reveal distinct sulfur peaks corresponding to different reaction stages. The sulfur-lithium correlation, dependent on solvent properties and battery state, provides insights into optimizing electrolyte compositions to suppress shuttle effects and facilitate desired cell reactions. In the future, this data can hopefully be used as part of a larger model including cycling data and shuttle current measurements to predict cell performance based on the chosen electrolyte composition. This work lays the fundamentals for the desired model and shows in principle that choosing the right electrolyte can help to facilitate certain cell reactions while suppressing others, which can help in suppressing the shuttle mechanism while still maintaining high capacity.