Upon the maturation and saturation of Li-ion battery technologies, the demand for the development of energy storage systems with higher energy densities has surged to meet the needs of key markets such as electric vehicles. Among the many next generation high-energy storage options, the Li-S battery system is considered particularly close to mass commercialization because of its low cost and the natural abundance of sulfur. In this review, we focus on nanostructured Li2S materials for Li-S batteries. Due to a lithium source in its molecular structure, Li2S can be coupled with various Li-free anode materials, thereby giving it the potential to surmount many of the problems related with a Li-metal anode. The hurdles that impede the full utilization of Li2S materials include its high activation barrier and the low electrical conductivity of bulk Li2S particles. Various strategies that can be used to assist the activation process and facilitate electrical transport are analyzed. To provide insight into the opportunities specific to Li2S materials, we highlight some major advances and results that have been achieved in the development of metal Li-free full cells and all-solid-state cells based on Li2S cathodes. (C) 2016 Elsevier B.V. All rights reserved.