Abstract The severe shuttle effect and sluggish conversion kinetics of lithium polysulfides impede the commercialization of lithium/sulfur (Li/S) batteries. To address this issue, a composite consists of Co-doped oxygen-deficient TiO2 coated by carbon layer (Co/TiO2-x@carbon) is proposed as a high-performance sulfur host. It was fabricated by one-step hydrothermal synthesis, follow by chemical vapor deposition method. The oxygen defects on the surface of Co/TiO2-x@carbon enhanced its electrical conductivity and strengthened the chemical interactions with polysulfides toward superior sulfur confinement. Moreover, the carbon coating layer has a hollow spherical architecture that can accelerate electron or ion transportation. Additionally, the Co nanoparticles promote sulfur redox conversion. Benefiting from these synergistic features, the S/Co/TiO2-x@carbon electrode delivers outstanding cycling stability (the capacity decay rate of 0.044% per cycle after 500 cycles) and a superior rate performance (972 mAh g-1 at 2.0 C).

中文翻译：

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碳层包覆钴掺杂缺氧二氧化钛作为锂/硫电池的高性能硫主体

摘要 多硫化锂严重的穿梭效应和缓慢的转化动力学阻碍了锂/硫（Li/S）电池的商业化。为了解决这个问题，提出了一种由碳层包覆的 Co 掺杂的缺氧 TiO2（Co/TiO2-x@carbon）组成的复合材料作为高性能硫主体。它是通过一步水热合成，然后是化学气相沉积法制造的。Co/TiO2-x@carbon 表面的氧缺陷增强了其导电性，并加强了与多硫化物的化学相互作用，从而实现了更好的硫限制。此外，碳涂层具有中空球形结构，可以加速电子或离子传输。此外，Co 纳米颗粒促进硫氧化还原转化。受益于这些协同功能，