Lithium-sulfur (Li-S) batteries are a promising next-generation energy-storage system due to their high theoretical energy density and low cost. However, the rapid capacity fading of high-sulfur-loading cathodes caused by the shuttle of soluble polysulfide intermediates between two electrodes heavily hinders the development of high-energy-density Li-S batteries. We develop in this work a powerful functional separator to suppress the polysulfide shuttle by coating two-dimensional nitrogen-doped porous carbon nanosheets on one surface of a commercial polypropylene separator. The high surface area, high content of nitrogen dopants, and close-packing laminar structure of the two-dimensional porous carbon nanosheets make them ideal to fabricate a lightweight and thin separator for high-energy-density Li-S batteries. The separator reported in this work endows the high-sulfur-loading cathodes made of commercial carbon materials with significantly enhanced performances that are comparable with or even superior to the state-of-the-art sulfur composite cathodes, opening up new opportunities for designing practical high-energy-density Li-S batteries.

锂硫（Li-S）电池具有较高的理论能量密度和较低的成本，是一种很有前途的下一代储能系统。然而，由于可溶性多硫化物中间体在两个电极之间的穿梭而引起的高硫负载阴极的快速容量衰减严重地阻碍了高能量密度Li-S电池的发展。在这项工作中，我们开发了一种功能强大的功能性隔板，可通过在商用聚丙烯隔板的一个表面上涂覆二维氮掺杂多孔碳纳米片来抑制多硫化物的穿梭。二维多孔碳纳米片的高表面积，高含量的氮掺杂剂以及紧密堆积的层状结构，使其成为制造轻薄型高能密度Li-S电池隔膜的理想之选。