The dissolution and shuttle of lithium polysulfides (LiPSs) should be primarily responsible for rapid capacity decay in lithium‐sulfur batteries (LSBs), which severely limits sulfur utilization. Introduction of cathode additives that can immobilize and rapidly convert LiPSs has been identified as effective in alleviating the shuttle effect. In this study, N/S codoped carbon dots (NSCDs) have been synthesized via a typical hydrothermal method, whose surfaces are rich in polar functional groups (─COOH, ─OH, ─SO3, and ─NH2) to capture LiPSs and effectively modulate the deposition behavior of Li2S. NSCDs as an additive of cathode significantly improve the battery discharge capacity and cycle life that it could deliver a reversible specific capacity of 1207.2 mAh g−1 at a current density of 0.2 C and stably operate for over 400 cycles at 1 and 2 C current densities. This work provides valuable insights into the application of 0D carbon nanomaterials in the field of LSBs.

中文翻译：

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N/S 共掺杂碳点在高效捕获和转化锂多硫化物中的关键作用


多硫化锂 （LiPS） 的溶解和穿梭应该是锂硫电池 （LSB） 容量快速衰减的主要原因，这严重限制了硫的利用。引入可以固定和快速转化 LiPSs 的阴极添加剂已被确定可有效缓解穿梭效应。本研究通过典型的水热法合成了 N/S 共掺杂碳点 （NSCDs），其表面富含极性官能团（─COOH、─OH、─SO3 和 ─NH2）以捕获 LiPSs 并有效调节 Li2S 的沉积行为。NSCD 作为阴极添加剂，显著提高了电池的放电容量和循环寿命，它可以在 0.2 C 的电流密度下提供 1207.2 mAh g-1 的可逆比容量，并在 1 和 2 C 电流密度下稳定运行超过 400 次循环。这项工作为 0D 碳纳米材料在 LSBs 领域的应用提供了有价值的见解。