Recent research trends in Li-S batteries

Lithium-sulfur (Li-S) batteries have recently attracted enormous attention in the energy-storage sector owing to their high theoretical capacities (1675 mA h g(-1)), high theoretical energy densities (2600 W h kg(-1)), and cost-effectiveness compared to the state-of-the-art Li-ion batteries. Despite these merits, the practical application of Li-S battery technology is hindered by certain severe drawbacks. Therefore, current challenges need to be diagnosed in order to find effective solutions to these Li-S battery-commercialization obstacles. To help direct future work, we not only summarize current research trends, but also highlight an effective solution for the practical applications of Li-S batteries. In this review, we thoroughly summarize current research work on three kinds of Li-S battery systems based on different cathode materials, namely sulfur (S-8), lithium sulfide, and sulfurized-polyacrylonitrile. In addition, we also provide insight into the current challenges associated with Li-metal anodes in Li-S batteries. We then summarize and discuss an effective solution to these issues, namely the use of Li-metal-free anodes or all-solid state electrolytes in Li-S full cell systems.