Despite lithium sulfur battery (LSB) has drawn extensive interest as a next-generation rechargeable battery due to its high energy densities, the practical application of LSB is limited by its intrinsic hurdles such as dendrite growth, polysulfides shuttling effect and limited sulfur loading and its utilization. Li-metal protection is an important issue in overcoming those challenges. We report unusually high ionic conductivity in 2D MoS₂ nanofilm exceeding 1 S/cm, which is more than two orders of magnitude when compared to that of conventional solid ionic materials. Based on the superior property, MoS₂ provides a wide range of benefits for LSB by preventing Li dendrites, protecting Li metal against corrosion, and facilitating high ionic-conducting and catalytic effect expediting the redox kinetics of LiPSs conversion. Herein, we present the successful implementation of MoS₂ for LSB with significantly improved performance and safety of LSBs when used as a protective coating for Li-metal anode as well as catalysts in cathode for polysulfide conversion.