Sulfur Solutions: Advancing High Voltage and High Energy Lithium Batteries with Organosulfur Electrolytes

Abstract

Achieving energy densities exceeding 350 Wh kg−1 while operating at elevated voltages (>4.5 V vs Li/Li+) is attainable through judicious selection of electrochemical pairs at the cathode and anode. However, current state‐of‐the‐art electrolytes exhibit limited stability when exposed to systems operating at or above 4.3 V. This limitation contributes to the degradation of electrode materials and raises critical safety concerns, impeding the commercialization of such systems. Consequently, there has been a notable surge in research efforts aimed at developing innovative electrolyte compositions capable of supporting high‐voltage lithium‐ion batteries (LIBs). A substantial portion of this research has focused on the family of organosulfur molecules, which possess high oxidative stability. Organosulfur salts also facilitate the formation of dense, ionically conductive solid electrolyte interfaces (SEI) and demonstrate excellent solubility. This article provides a comprehensive overview of the field of organosulfur electrolyte components for their applications in energy storage, encompassing solvents, alternative conducting salts, and additives. It emphasizes the idea that the deliberate design of electrolyte compositions is instrumental in controlling electrode passivation, with organosulfur‐based structures historically proving advantageous in every aspect of the electrolyte. Crucially, it should be noted that many of these components are commercially available, holding significant implications for industrial applications.

Nonsolvating Fluoroaromatic Cosolvent Enabled Long-Term Cycling of High-Voltage Lithium-Ion Batteries with Organosulfur Electrolytes

“…Gibbs free energies were determined at a temperature of 298.15 K, considering both the zero-point energy and thermal correction derived from the vibrational frequencies. Solvation calculations were performed using the self-consistent reaction field (SCRF) method, with the inclusion of an implicit solvent represented by the polarizable continuum model (PCM) and the dielectric properties of EMS (dielectric constant = 58) . The oxidation and reduction potentials relative to the Li/Li + reference were calculated using the following equations: E ox true( normalV .25em vs .25em Li Li + true) = G false( normalA + false) − G false( normalA false) F − 1.4 V E red true( normalV .25em vs .25em Li Li + true) = − G false( normalA − false) − G false( normalA false) F − 1.4 V where G (A), G (A + ), and G (A – ) are the free energies of the molecule A, its oxidized, and reduced species, respectively.…”

“…Solvation calculations were performed using the self-consistent reaction field (SCRF) method, with the inclusion of an implicit solvent represented by the polarizable continuum model (PCM) and the dielectric properties of EMS (dielectric constant = 58). 56 The oxidation and reduction potentials relative to the Li/Li + reference were calculated using the following equations: 57…”