Key challenges, recent advances and future perspectives of rechargeable lithium-sulfur batteries

Lithium-sulfur (Li-S) battery, which releases energy by coupling high abundant sulfur with lithium metal, is considered as a potential substitute for the current lithium-ion battery. Thanks to the lightweight and multi-electron reaction of sulfur cathode, the Li-S battery can achieve a high theoretical specific capacity of 1675 mAh g−1 and specific energy of 2600 Wh kg−1. However, some key scientific issues limit its practical application, such as the “shuttle effect” of lithium polysulfides, large volume change, poor conductivity of sulfur and its solid-state products, and self-discharge phenomenon. Of these, the “shuttle effect” is recognized as the most critical challenge affecting on electrochemical performance. Hence, this review first systematically introduces the development of Li-S batteries and the corresponding “shuttle effect”. Then, the latest work on anode, cathode, separator and electrolyte are summarized. Finally, some promising views on the future research direction of this battery system are put forward.