Advanced rechargeable batteries with high energy densities may soon power portable electronic devices and electric vehicles in the future. Among all candidates, lithium-sulfur (Li-S) batteries are considered one of the most promising next-generation secondary batteries because of their high theoretical specific capacity and theoretical energy density. At present, the research and development of Li-S batteries mainly focus on the design and synthesis of high performance sulfur cathode materials. Porous carbon materials with good electronic conductivity, high structural stability, and well-developed porous structure, such as the activated carbon, mesoporous carbon, ultra-microporous carbon, hierarchical porous carbon, hollow carbon sphere, and hollow carbon fiber, have been proved to be the effective carbon matrix materials for sulfur cathodes. This article presents the recent developments of the porous carbon/sulfur composite materials for Li-S battery cathodes. The electrochemical performances of the porous carbons with tailored pore structure characteristics for the impregnation of sulfur are summarized. Furthermore, the impacts of various porous structures on the Li-S battery performances have been discussed. Accordingly, the future developments of Li-S battery platforms are discussed from the perspectives of the advanced engineering and synthesis of porous carbon/sulfur composite cathode materials.

Contents
1 Introduction
2 Porous carbon/sulfur composite cathode materials
2.1 Activated carbon/sulfur composites
2.2 Mesoporous carbon/sulfur composites
2.3 Ultra-microporous carbon/sulfur composites
2.4 Hierarchical porous carbon/sulfur composites
2.5 Hollow carbon sphere/sulfur composites
2.6 Hollow carbon fiber/sulfur composites
3 Conclusion