锂硫电池具有高的理论比容量和理论能量密度,被认为是当前最有前景的二次电池体系之一。现阶段锂硫电池的研究工作主要集中于高性能硫正极材料的设计与合成。具有优良的导电性、良好的结构稳定性和多孔结构的纳米碳材料,比如活性碳、介孔碳、超小微孔碳、多级结构多孔碳、空心碳球和空心碳纤维,充分满足了锂硫电池正极材料对碳基体的要求。本文综述了近年来多孔碳/硫复合材料作为硫正极的研究进展。总结了以具有不同结构特征的多孔碳基体负载硫组装的锂硫电池的电化学性能,并分析了不同多孔结构对性能的影响。最后在此基础上,从多孔碳/硫复合正极材料的设计和合成的角度,展望了其未来的发展趋势。
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.