硫负载方式调控碳/硫复合材料结构及锂-硫电池性能研究

Controlling Structure of Carbon/Sulfur Composite Materials by Sulfur-loading Methods and Studying Performance of Lithium-sulfur Batteries

碳/硫(C/S)复合材料的硫负载方式调控可以改善聚硫化物的穿梭效应,提升锂-硫电池的容量。物理硫负载法容易导致循环过程中硫的脱落,化学硫负载法不利于倍率性能的提升。采用物理硫负载和化学硫负载相结合的方式,对提升C/S复合材料的循环稳定性和倍率性能具有重要意义。本文控制C/S复合材料的硫负载方式,研究化学硫负载制得的C/S复合材料在热处理前后的结构和性能变化,有利于实现稳定的聚硫化物转化,提升锂-硫电池循环稳定性和倍率性能。结果表明:C/S煅烧后复合电极具有较好的循环稳定性(5C下的容量保持率为60%)和倍率性能(60 mAh·g^(-1)20C),这是因为其具有稳定的聚硫化物转化能力。

The sulfur loading mode of carbon/sulfur(C/S)composite materials can improve the shuttle effect of polysulfide and increase the capacity of lithium-sulfur batteries.The physical sul-fur loading method is easy to lead to the loss of sulfur during the cycle,and the chemical sulfur loading method is not conducive to the improvement of the magnification performance.The combi-nation of physical sulfur loading and chemical sulfur loading is of great significance to improve the cycle stability and rate performance of C/S Composite materials.The structure and properties of C/S composites prepared by chemical sulfur loading are studied by controlling the sulfur loading mode,which is conducive to realizing stable polysulfide conversion and improving the cycle stabili-ty and rate performance of lithium-sulfur batteries.The results show that the C/S calcined com-posite electrode has good cyclic stability(60%capacity retention under 5C)and rate performance(60 mAh·g^(-1)20C),which is due to its stable polysulfide conversion ability.