Lithium-sulfur batteries have been attracting considerable research attention due to their high energy densities and low costs. However, one of their main challenges is the undesired shuttling of polysulfides, causing rapid capacity degradation. Herein, we report the first example of sulfiphilic VSe₂ ultrafine nanocrystals immobilized on nitrogen-doped graphene to modify the battery separator for alleviating the shuttling problem. VSe₂ nanocrystals provide numerous active sites for chemisorption of polysulfides as well as benefit the nucleation and growth of Li₂S. Furthermore, the kinetic reactions are accelerated which is confirmed by higher exchange current density and higher lithium ion diffusion coefficient. And the first-principles calculations further show that the exposed sulfiphilic planes of VSe₂ boost the redox of Li₂S. When used as separators within the lithium sulfur batteries, the cell indicates greatly enhanced electrochemical performances with excellent long cycling stability and exceptional rate capability up to 8 C. Moreover, it delivers a higher areal capacity of 4.04 mAh·cm⁻² as well as superior cycling stability with sulfur areal loading up to 6.1 mg·cm⁻². The present strategy can encourage us in engineering novel multifunctional separators for energy-storage devices.

锂硫电池由于其高能量密度和低成本而受到了相当多的研究关注。然而，它们的主要挑战之一是多硫化物的不期望的穿梭，从而导致容量快速下降。在本文中，我们报告了固定在氮掺杂石墨烯上的亚硫基VSe ₂超细纳米晶体的第一个实例，该电池修饰了电池隔膜以减轻穿梭问题。VSe ₂纳米晶体提供了许多化学吸附多硫化物的活性位点，并且有利于Li ₂的成核和生长此外，动力学反应被加速，这被更高的交换电流密度和更高的锂离子扩散系数所证实。第一性原理计算进一步表明，暴露的VSe _2的亚磺酸平面促进了Li ₂ S的氧化还原。当在锂硫电池中用作隔膜时，该电池表明其电化学性能大大增强，具有出色的长循环稳定性和出色的倍率性能最高温度可达8C。此外，它的最高单位面积容量为4.04 mAh·cm ^-2，在硫的单位面积负载高达6.1 mg·cm ^{-2的情况下}具有出色的循环稳定性。当前的策略可以鼓励我们设计用于储能装置的新型多功能隔板。