Lithium-sulfur (Li-S) batteries are considered to be one of the most promising candidate systems for next-generation electrochemical energy storage. The major challenge of this system is the polysulfide shuttle, which results in poor cycling efficiency. In this work, a highly N-doped carbon/graphene (NC/G) sheet is designed as a sulfur host, which combines the merits of abundant N active sites and high electrical conductivity to achieve in situ anchoring-conversion of lithium polysulfides (LiPSs). Such a host not only has strong binding with LiPSs but also promotes redox kinetics, which are revealed by both experimental investigations and theoretical studies. The sulfur cathode based on the NC/G host exhibits a high initial capacity of 1380 mA h g-1 and a superior cycle stability with a low capacity decay of 0.037% per cycle within 500 cycles at 2 C. Steady areal capacity with a high sulfur loading (5.6 mg cm-2 ) is also attained even without the addition of LiNO3 in the electrolyte. This work proposes and illustrates the importance of in situ anchoring-conversion of LiPSs, offering a new strategy to design multifunctional sulfur hosts for high-performance Li-S batteries.

中文翻译：

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将电导率，固定性和催化能力整合到高氮碳/石墨烯片材中作为有效的硫基质。

锂硫（Li-S）电池被认为是下一代电化学能量存储最有希望的候选系统之一。该系统的主要挑战是多硫化物梭，其导致差的循环效率。在这项工作中，将高氮掺杂的碳/石墨烯（NC / G）片材设计为硫主体，它结合了丰富的N活性位和高电导率的优点，从而实现了多硫化锂（LiPSs）的原位锚固转化。 ）。这样的宿主不仅与LiPS具有强结合力，而且还促进了氧化还原动力学，这在实验研究和理论研究中都得到了揭示。基于NC / G主体的硫阴极显示出1380 mA h g-1的高初始容量和出色的循环稳定性以及低的0容量衰减。在2 C的500个循环中，每个循环的密度为037％。即使在电解液中不添加LiNO3，也可以获得具有高硫负荷（5.6 mg cm-2）的稳定面容量。这项工作提出并说明了LiPS原位锚固转换的重要性，为设计高性能Li-S电池的多功能硫基质提供了新的策略。