Small Molecules, Great Powers: Chemistry of Small Organo‐Chalcogenide Molecules in Rechargeable Li‐Sulfur Batteries

Abstract

Small organic chalcogenides molecules are receiving more attention in conjunction with the development of rechargeable lithium metal batteries (LMBs) especially lithium-sulfur (Li−S) batteries due to their abundant resources, reversible redox, high capacities, tunable structures, unique functional adjustability, and strong interaction with congener polysulfides. In this review, the working principles are generalized of small organo-chalcogenide molecules in three important parts of batteries: electrolyte, interface, and cathode. First, in terms of regulating kinetics in electrolyte, small organochalcogenide molecules can not only act as redox mediator to accelerate the redox kinetics of sulfur, but also change the inherently slow solid-solid process to form a faster redox pathway, which will bring light to the development of cryogenic Li−S batteries. Second, for interface chemistry, the introduction of small organo-chalcogenide molecules can construct more elastic and stable anodic single-SEI or cathodic/anodic dual-SEI, thus effectively improving the cycling stability of batteries. Third, small organo-chalcogenide molecules can be used as cathode materials in the form of liquid phase, solid phase, or precursor of polymers. Finally, advised optimizations are proposed about further mechanism deciphering, battery configuration design, machine learning, thereby providing direction to bridge the gap between rational modulation and practical battery implementation for small organochalcogenide molecules.

Kinetically Favorable Li–S Battery Electrolytes

“…Organosulfide is regarded as a promising endogenous co-mediator in Li–S batteries, whereas it can also be directly used as the liquid sulfur-equivalent cathode. , Encouragingly, it helps to construct a novel liquid–liquid interface between cathode and electrolyte, thereby bypassing the sluggish solid–liquid conversion process of traditional inorganic sulfur at the initial discharging stage. Consequently, fast interfacial reaction kinetics and high active material utilization can be readily obtained.…”

Interface engineering toward stable lithium–sulfur batteries

“…327 Especially, with the development of machine learning, a comprehensive analysis of the effect of key factors on the battery performance, corresponding electrode materials/ electrolyte design, and the reaction mechanism investigation can be realized. [329][330][331][332][333] Machine learning can solve the challenges involving large, complex, and unexplored structures and data, greatly reducing trial-and-error costs and improving research efficiency.…”

Design of Wide‐Temperature Lithium‐Sulfur Batteries

“…[27] The charging temperature range of wide-temperature batteries is between À 20 °C ~60 °C. [28] Owing to the diversity of climate required to extend the working temperature limit of lithium batteries to below À 50 °C or above 100 °C to meet the operation of more extreme electronic equipment (underground or space exploration). [29] However, current LiÀ S batteries operating at low or high temperatures usually deteriorate the electrochemical performance and even lead to thermal runaway, severely limiting the application of widetemperature LiÀ S batteries.…”