锂-硫电池研究现状及展望

锂-硫电池由于具有高比能量以及硫廉价易得等优势而受到人们的广泛关注. 但其实际应用仍面临着来自于正极、电解液以及负极等方面的诸多挑战，具体包括硫正极的溶解、多硫化合物的“穿梭效应”及金属锂负极的枝晶问题. 本文以课题组近期的研究结果为主线，综述了近两年来关于锂-硫电池的研究进展，重点探讨了碳硫复合物正极、硫化锂正极、复合隔膜设计和电解液方面的研究进展，并总结了各方面存在的问题.

Advances and Prospects of Lithium-Sulfur Batteries

Lithium-sulfur batteries have recently attracted worldwide attention due to the high specific theoretical energy density of sulfur cathode (2600 Wh•kg^-1), low cost and wide availability of sulfur. However, the practical application of lithium-sulfur batteries has been hindered by several challenges, such as the shuttling of polysulfide intermediates, the large volume expansion of sulfur during charge/discharge and the dendrites formation on lithium anode. Foremost among these is the shuttling effect arising from the dissolution of lithium polysulfides intermediate into the electrolyte from the cathode reaction and their diffusion to the anode where they react with metal lithium to form lower-ordered lithium sulfides that then return to the cathode, which results in the poor cycling stability and severe self-discharge. This review summarizes the recent research advances in the sulfur cathode, battery structures, electrolytes and lithium sulfide cathode to mitigate the shuttling effect of lithium polysulfides. The possible solutions proposed by our groups to mitigate the shuttling effect are introduced from the aspects of sulfur cathode, design of composite Celgard, electrolytes and lithium sulfide (Li₂S) cathode. Finally, perspectives and future developments of lithium-sulfur batteries are pointed out based on our previous studies and experiences.