Revitalizing Li–S batteries: the power of electrolyte additives

Abstract

Lithium–sulfur (Li–S) batteries have garnered significant attention as promising next-generation energy storage solutions due to their high energy density and cost efficiency. However, the broad adoption of Li–S batteries is impeded by several critical issues. These include the intrinsically low conductivities of sulfur (S) and lithium sulfide (Li₂S), the polysulfide shuttle effect, and dendrite formation on the lithium (Li) electrode, among other challenges. Overcoming these obstacles is crucial to realizing the full potential of Li–S batteries. A key step towards improving Li–S battery performance is the optimization of electrolytes, with a particular focus on enhancing cell cyclability, rate capability, safety, and lifespan. This review examines the current advancements in various electrolyte additive options, including their concepts, designs, and materials, and how the electrolyte's final chemical and physical properties influence the overall performance of Li–S batteries. The aim is to provide a comprehensive framework for the rational selection of future electrolyte additives for Li–S batteries, based on the available concepts, and to evaluate the existing electrolyte additives.