The preparation of functional separator has become an effective strategy to enhance the electrochemical performance of lithium-sulfur batteries (LSBs). Therefore, a functional separator suitable for LSBs has aroused great interest. In this work, we report a novel functional separator using LiVPO₄F together with carbon nanotube (LVPF/CNT) as functional coating. The LVPF/CNT modified separator not only acts as a conductive layer to facilitate electron and lithium ion (Li⁺) transport, but also provides chemisorption for lithium polysulfides (LiPSs) and improves the electrochemical kinetics of LSBs. Thus, the cell with LVPF/CNT modified separator delivers an excellent cycle life with the capacity of 578.5 mAh g^-1 after 1000 cycles at 1.5 C. An ultra-long cycle life (551 mAh g^-1 after 350 cycles at 0.5 C) and a high areal capacity of 5.58 mAh cm^-2 are obtained at a high sulfur loading of 7 mg cm^-2. Moreover, the visualized transformation of the LiPSs in the tailor-made cell is also revealed by in situ XRD, while the density functional theory (DFT) simulated the principle of the interaction between the LVPF and LiPSs. This work provides a promising and insightful research to develop the progressive LSBs with functional separator.

功能性隔板的制备已成为增强锂硫电池（LSBs）电化学性能的有效策略。因此，适用于LSB的功能分离器引起了极大的兴趣。在这项工作中，我们报告了使用LiVPO ₄ F和碳纳米管（LVPF / CNT）作为功能涂层的新型功能性隔板。LVPF / CNT改性隔膜不仅充当导电层以促进电子和锂离子（Li ⁺）传输，而且还提供了多硫化锂（LiPSs）的化学吸附作用并改善了LSB的电化学动力学。因此，带有LVPF / CNT改性隔膜的电池可提供出色的循环寿命，容量为578.5 mAh g ^-1在1.5 C下进行1000次循环后。在7 mg cm ^-2的高硫负荷下获得超长循环寿命（在0.5 C下350次循环后为551 mAh g ^-1）和5.58 mAh cm ^-2的高面积容量。此外，原位XRD还揭示了定制电池中LiPS的可视化转化，而密度泛函理论（DFT）模拟了LVPF和LiPS之间相互作用的原理。这项工作为开发具有功能分离器的渐进式LSB提供了有前途和深刻的研究。