Recent progress in host and electrolyte engineering towards Li ₂ S cathode for lithium-sulfur battery

Lithium sulfide (Li₂S) has drawn much attention owing to its super-high theoretical specific capacity and energy density, as well as its compatibility with lithium-free anode materials. However, the commercialization of Li₂S cathode is severely hindered by its poor rate capability and short cyclic life arising from its poor electrical conductivity, high activation energy barrier and shuttle effect of polysulfide intermediates. Many approaches have been reported, mainly focusing on the development of host for Li₂S cathode as well as electrolyte engineering, which have achieved great progress. This Review firstly provides an in-depth discussion of the challenges encountered Li₂S cathode, subsequently discusses the host design for Li₂S cathode and electrolyte engineering, focusing on the fundamental mechanism underlying the host or electrolyte engineering for improving the reaction kinetics and interface stability. Finally, the remaining challenges and future directions of Li₂S cathode are discussed to further improve the performance of Li₂S cathode materials and promote their practical application.