context: Lithium sulfur batteries (LSBs) with high theoretical energy densities of 2600 W h kg−1 are considered promising candidates to take precedence over lithium ion batteries (LIBs) in meeting the emerging and demanding applications, such as electric vehicles and smart grids. However, the practical implementation of LSBs is plagued by several fundamental challenges, including the dissolution and shuttling of lithium polysulfides (LPSs), the insulating nature of sulfur and lithium sulfides, and the instability of Li metal anodes. In the past decade, progress in structural design and materials chemistry has induced discernible improvements in battery performance. For instance, a high sulfur utilization of 1620 mA h g−1 with long cycle life of 1000 cycles was reported for sulfur/graphene composite electrodes. However, statistical analysis of the reported cathodes indicates that the major cathodes tested under low sulfur loadings (<2 mg cm−2) and high electrolyte/sulfur (E/S) ratios (>10 μL mg−1) are unacceptable for practical applications. Based on theoretical estimations, LSBs should possess sulfur loadings of above 7 mg cm−2, areal capacities of over 6 mA h cm−2, and E/S ratios of less than 5 μL mg−1, to outperform current LIBs in terms of the practical energy density.