Lithium-sulfur (Li-S) batteries are receiving a growing appreciation from the academic community and industry due to their relatively high theoretical energy density and low-cost raw materials. However, their commercialization strongly depends on overcoming the shuttle effect caused by Li polysulfide species (LiPSs), the low utilization efficiency of active S material, and the uncontrolled growth of Li dendrites. Electrolytes can be the key to these issues and promote the reaction kinetics of Li-S batteries through electrolyte engineering. In this review, after introducing the development history and working mechanism of Li-S battery, advanced in-situ characterization techniques that facilitate insight into the underlying mechanism of Li-S batteries are discussed. Subsequently, various strategies for suppressing the shuttle effect of LiPSs are simply summarized. The role of LiPSs is thoroughly discussed and a comprehensive overview is provided, and the electrolyte engineering strategies for eliminating the dissolution of LiPSs and inhibiting the growth of Li dendrites in Li-S battery systems are focused. In addition, the controversy over suppressing versus promoting the dissolution of LiPSs to the bulk electrolyte is deeply discussed, and techniques and theoretical calculations for characterizing the solvation structure of Li⁺ ions are presented. Finally, prospects and personal perspectives are provided on electrolyte engineering as the future research directions for Li-S batteries.

锂硫（Li-S）电池由于其相对较高的理论能量密度和低成本的原材料，越来越受到学术界和工业界的重视。然而，它们的商业化很大程度上取决于克服锂多硫化物（LiPSs）引起的穿梭效应、活性硫材料的低利用效率以及锂枝晶不受控制的生长。电解质可能是解决这些问题的关键，并通过电解质工程促进锂硫电池的反应动力学。在这篇综述中，在介绍了锂硫电池的发展历史和工作机制之后，讨论了有助于深入了解锂硫电池潜在机制的先进原位表征技术。随后，简单总结了抑制 LiPS 穿梭效应的各种策略。深入讨论了 LiPS 的作用并提供了全面的概述，并重点介绍了消除 LiPS 溶解和抑制 Li-S 电池系统中锂枝晶生长的电解质工程策略。此外，深入讨论了抑制与促进 LiPSs 溶解到体电解质的争论，以及表征 Li 溶剂化结构的技术和理论计算⁺离子出现。最后，提供了电解质工程作为锂硫电池未来研究方向的前景和个人观点。