Lithium sulfur batteries with high energy densities are promising next-generation energy storage systems. However, shuttling and sluggish conversion of polysulfides to solid lithium sulfides limit the full utilization of active materials. Physical/chemical confinement is useful for anchoring polysulfides, but not effective for utilizing the blocked intermediates. Here, we employ black phosphorus quantum dots as electrocatalysts to overcome these issues. Both the experimental and theoretical results reveal that black phosphorus quantum dots effectively adsorb and catalyze polysulfide conversion. The activity is attributed to the numerous catalytically active sites on the edges of the quantum dots. In the presence of a small amount of black phosphorus quantum dots, the porous carbon/sulfur cathodes exhibit rapid reaction kinetics and no shuttling of polysulfides, enabling a low capacity fading rate (0.027% per cycle over 1000 cycles) and high areal capacities. Our findings demonstrate application of a metal-free quantum dot catalyst for high energy rechargeable batteries.

中文翻译：

---

无穿梭锂硫电池中黑磷量子点的出色催化作用。

具有高能量密度的锂硫电池是有前途的下一代储能系统。然而，多硫化物向固体硫化锂的穿梭和缓慢的转化限制了活性材料的充分利用。物理/化学限制可用于锚定多硫化物，但对利用封闭的中间体无效。在这里，我们采用黑磷量子点作为电催化剂来克服这些问题。实验和理论结果均表明，黑磷量子点有效吸附和催化了多硫化物的转化。活性归因于量子点边缘上的大量催化活性位点。在存在少量黑磷量子点的情况下，多孔碳/硫阴极显示出快速的反应动力学，并且没有多硫化物的穿梭作用，从而实现了低容量衰减率（在1000个循环中，每个循环为0.027％）和较高的面容量。我们的发现证明了无金属量子点催化剂在高能可充电电池中的应用。