Abstract: Conventional lithium-ion (Li-ion) batteries become difficult to satisfy requirements of high-energy batteries due to environmental crisis as well as rapid developments of electronic and electromotive devices. The pursuit of battery system with high-energy density is the research hotspot in the domain of energy storage. Lithium-sulfur (Li-S) batteries are considered as one of the most promising energy storage systems due to high energy density, low cost, and environmental friendliness. However, the disadvantages of sulfur electrodes such as low electronic/ionic conductivity, large volume change during cycling, the dissolution of intermediates and the concomitant "shuttle effect", as well as dentrite formation in lithium anodes, hinder the commercialization of Li-S batteries. The employment of carbon-based materials in Li-S systems increases the electrode conductivity, buffers the volume change, and inhibits the polysulfide shuttle, presenting as an effective strategy in enhancing the electrochemical performance of Li-S batteries. In this paper, we review the most recent development of carbon-based materials applied in Li-S systems, including sulfur/carbon composites, carbon interlayers, self-standing/flexible electrodes and carbon-based anodes, present new insights of connection between carbon structures and improvement of sulfur electrochemical performance, and propose some critical issues in Li-S batteries as well as directions for its future developments.

Key words: lithium-sulfur batteries, carbon materials, sulfur/carbon composite, carbon interlayer, flexible batteries, carbon anode