Sulfur-containing polymer with covalent C-S bonds has become an ideal alternative cathode of element sulfur for lithium-sulfur battery. However, the rational design of polymer structure with high sulfur content and enhanced electrochemical performance of Li-S battery is still a great challenge. In this study, a facial synthesis of sulfur-containing polymer by using 1,2,3-trichloropropane and sulfur as starting materials at a mild condition was reported, and the covalent anchoring of the C-S bonds within the polymer effectively inhibited the shuttle effect of polysulfides, providing a splendid internal environment for the diffusion of lithium ions. As a result, the rich sulfur content (higher than 80 %) and its homogeneous distribution in the polymer backbone determined the excellent rate performance of obtained sulfur-containing polymers. In terms of cycling performance, the reversible specific capacity of the battery is 396 mAh/g after 500 cycles at a current density of 0.5 A/g and 350 mAh/g after 800 cycles at 1 A/g, with a capacity decay of only 0.06 % per cycle.

中文翻译：

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用于提高锂硫电池倍率和循环性能的含硫聚合物


具有共价CS键的含硫聚合物已成为锂硫电池理想的元素硫替代正极。然而，合理设计高硫含量的聚合物结构并增强锂硫电池的电化学性能仍然是一个巨大的挑战。本研究报道了以1,2,3-三氯丙烷和硫磺为起始原料，在温和条件下表面合成含硫聚合物，聚合物内CS键的共价锚定有效抑制了硫磺的穿梭效应。多硫化物，为锂离子的扩散提供了良好的内部环境。因此，丰富的硫含量（高于80%）及其在聚合物主链中的均匀分布决定了所得含硫聚合物优异的倍率性能。循环性能方面，电池在0.5 A/g电流密度下循环500次后可逆比容量为396 mAh/g，在1 A/g电流密度下循环800次后可逆比容量为350 mAh/g，容量衰减仅为每个周期 0.06%。