Abstract Lithium sulfur (Li S) batteries are promising alternatives to conventional Li-ion batteries in terms of specific capacity and energy. However, the technical challenges raised from the soluble polysulfide (PS) in organic electrolyte deter their implementation in practical applications. Nanoengineered structure and chemical adsorptive materials hold great promise in mitigating the PS migration problem. Here, we develop a tubular titanium oxide (TiO2)/reduced graphene oxide (rGO) composite structure (TG) as a sulfur hosting material for constructing better performed Li S batteries. The TG/sulfur cathode (TG/S) is able to deliver ∼1200 mAh g−1 specific capacity with stable operation for over 550 cycles. Moreover, the TG/S composite cathode shows stable Coulombic efficiencies of over ∼95% at various C rates, which are ∼10% higher than those of the rGO/sulfur (G/S) counterparts. The superior electrochemical performances of TG/S could be ascribed to the synergistic effects between the conductive rGO support and the physically/chemically absorptive TiO2, that is, the spatial tubular structure of TiO2 provides intimate contact and physical confinement for sulfur, while the polar TiO2 in TG/S shows strong chemical interaction towards the sulfur species.

中文翻译：

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管状氧化钛/还原氧化石墨烯-硫复合材料可提高锂硫电池的性能

摘要 锂硫（Li S）电池在比容量和能量方面是传统锂离子电池的有前途的替代品。然而，有机电解质中可溶性多硫化物（PS）带来的技术挑战阻碍了它们在实际应用中的实施。纳米工程结构和化学吸附材料在减轻 PS 迁移问题方面具有很大的前景。在这里，我们开发了管状氧化钛（TiO2）/还原氧化石墨烯（rGO）复合结构（TG）作为硫承载材料，用于构建性能更好的锂硫电池。TG/硫正极（TG/S）能够提供~1200 mAh g-1的比容量，稳定运行超过550次循环。此外，TG/S 复合阴极在不同的 C 速率下显示出超过 95% 的稳定库仑效率，比 rGO/硫 (G/S) 对应物高约 10%。TG/S 优异的电化学性能可归因于导电 rGO 载体与物理/化学吸收性 TiO2 之间的协同效应，即 TiO2 的空间管状结构为硫提供了紧密接触和物理限制，而极性 TiO2在 TG/S 中显示出对硫物质的强烈化学相互作用。