Abstract:

 The conventional lithium-ion batteries are unable to meet the increasing demands for high-energy storage systems, because of their limited theoretical capacity. In recent years, intensive attentions have been paid on lithium-sulfur battery worldwide by researchers, due to its step-change improvement in capacity（1673 mA·h·g−1），which is 4 times higher than current lithium ion batteries. In response to the low electronic/ionic conductivity of sulfur, the dissolution of the polysulfide, the huge volume changes during cycling and so on, researchers have focused on the design of smart cathode structures, the protection of lithium anode, and the optimization of electrolyte and separators. These strategies successfully inhibit the polysulfide shuttling problem, increase the utilization of active substances, buffer the large volume change and improve the safety and cycle life. In this paper, we review the recent developments in lithium-sulfur batteries, highlight typical novel technologies such as polar-polar interactions to control polysulfide dissolution, artificial SEI to protect the lithium anode, novel electrolyte and separator to suppress polysulfide shuttling, and forecast the directions for its future developments.

Key words: lithium-sulfur batteries, sulfur cathode, lithium metal anode, electrolyte, separator