Although lithium–polysulfur (Li–polyS) batteries employing organic polymeric sulfur as a cathode material outperform the lithium–sulfur (Li–S) battery system, the relatively low sulfur loading (<2 mg cm^–2) in the current Li–polyS batteries compromises the areal capacity, constraining their practicality. We present here a new cathode active material (a covalently grafted polysulfur–graphene nanocomposite (polySGN)) for ultrahigh-loading Li–polyS batteries. The new cathode active material polySGN offers several advantages: (i) the well-dispersed graphene sheets offer highly electrically conductive pathways for electrons to travel within the polySGN matrix; (ii) the intermediate organosulfide moieties alleviate irreversible sulfide deposition on electrodes; and (iii) the in situ formed coating layer on the cathode-side surface of the polymeric separator further reduces polysulfide migration. The Li–polyS batteries employing polySGN as the cathode active material accomplish the highest sulfur loading (up to 10.5 mg cm^–2) and the highest areal capacity (∼12 mA h cm^–2) reported thus far in the literature.

中文翻译：

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共价接枝的多硫-石墨烯纳米复合材料，用于超高硫负载锂-多硫电池

尽管使用有机聚合硫作为正极材料的锂-聚硫（Li-polyS）电池优于锂-硫（Li-S）电池系统，但相对较低的硫负荷（<2 mg cm ^–2）在当前的Li-polyS电池中会损害面积容量，从而限制了其实用性。我们在这里介绍一种用于超高负载锂-聚硫电池的新型阴极活性材料（一种共价接枝的多硫-石墨烯纳米复合材料（polySGN））。新型阴极活性材料polySGN具有以下优点：（i）分散良好的石墨烯片为电子在polySGN基质中的传播提供了高度导电的途径；（ii）中间有机硫化物部分减轻了不可逆的硫化物在电极上的沉积；（iii）在聚合物隔板的阴极侧表面上原位形成的涂层进一步减少了多硫化物的迁移。使用polySGN作为正极活性物质的Li–polyS电池可实现最高的硫负荷（高达10.5 mg cm ^–2）和迄今为止文献中报道的最高面容量（〜12 mA h cm ^–2）。