Post lithium-sulfur battery era: challenges and opportunities towards practical application

Lithium-sulfur (Li-S) batteries have been regarded as a promising next-generation energy storage system owing to the high theoretical energy density and natural abundance of sulfur. Abundant fundamental researches have pushed the flourishing development on electrochemical behaviors in recent 20 years. It is time to evolve into post-Li-S battery era with the pursuit towards practical application. During the landmark leap, numerous new challenges appear under harsh conditions, such as high sulfur loading, low cathode density, lean electrolyte and limited lithium reservoir. Herein, we summarize the considerable parameters of punch Li-S cells and review the pioneering studies focused on the cathode structure, conversion kinetics, electrode interphase and battery safety. The interwoven relationship of these key points is concluded and discussed, which provides guidance to future researches aiming to safe and long-lifespan Li-S batteries with high energy density.