The shuttling effect of polysulfides species seriously deteriorates the performance of Li–S batteries, representing the major obstacle for their practical use. However, the exploration of ideal cathodes that can suppress the shuttling of all polysulfides species is challenging. Herein, we propose an ingenious and effective strategy for constructing hybrid-crystal-phase TiO₂/covalent organic framework (HCPT@COF) composites where hybrid anatase/rutile TiO₂ nanodots (10 nm) are uniformly embedded in the interlayers of porous COFs. The synthesis was realized via a multiple-step reaction relay accompanying by a pseudo-topotactic transformation of three-dimensional layered structures from 1,4-dicyanobenzene monomer-embedded Ti-intermediate networks to HCPT nanodots-embedded COF frameworks. The HCPT@COF/S cathodes show superior comprehensive performance such as high specific capacity, long cycling stability, and remarkable rate capability for Li–S batteries, owing to the complementary anchoring effect of hybrid anatase/rutile TiO₂ in the HCPT@COF composite, which is evidenced by substantial characterizations including X-ray photoelectron spectroscopy and density functional theory calculations.

中文翻译：

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混合锐钛矿/金红石纳米点嵌入式共价有机骨架，对高性能锂硫电池具有互补的多硫化物吸附能力

多硫化物物种的穿梭效应严重恶化了锂锂电池的性能，这是其实际使用的主要障碍。然而，探索能够抑制所有多硫化物物种穿梭的理想阴极是具有挑战性的。在这里，我们提出了一种巧妙而有效的策略来构造锐钛矿/金红石型TiO ₂杂化晶体相TiO ₂ /共价有机骨架（HCPT @ COF）复合材料纳米点（10 nm）均匀地嵌入多孔COF的中间层中。合成是通过多步反应中继实现的，同时伴随着三维分层结构从1,4-二氰基苯单体嵌入的Ti中间网络到HCPT纳米点嵌入的COF框架的拟定位转换。HCPT @ COF / S正极显示出优异的综合性能，例如高比容量，长循环稳定性和出色的Li-S电池倍率性能，这是由于HCPT @ COF复合物中锐钛矿/金红石混合TiO ₂具有互补的锚固作用，这由X射线光电子能谱和密度泛函理论计算等大量表征所证明。