Abstract: Lithium-sulfur battery (Li-S) has been regarded as one of the most promising energy storage system due to its high energy density, environmental friendly, low cost and abundant resources of sulfur. Recently, the technology development of Li-S battery has been largely improved with the progress of sulfur trapping chemistry and sulfur cathode design. However, the commercialization of Li-S battery is still encountering a series of challenges, such as design of high loading sulfur cathode, activation of sulfur in lean electrolyte or solid electrolyte, stable electrode/electrolyte interface, and safety concerns. In which, the safety issue of Li-S battery is one of the key factors, which impede the commercialization process. In recent years, some strategies have been proposed to address the safety concerns of Li-S battery, including protection of Li metal anode, flame retardant electrolyte, modification of separator, solid electrolyte and accommodation of volume change during discharge and charge. In this review contribution, we summarize the research progress on the safety issue of Li-S battery, and discuss the future development of commercially available high-performance Li-S batteries featuring high energy density, stable cycle and high safety.

Key words: lithium-sulfur battery, safe property, flame retardant electrolyte, solid electrolyte