Yue Bin, Wang Lili, Zhang Ningyuan, Xie Yunrui, Yu Wensheng, Ma Qianli, Wang Jinxian, Liu Guixia, Dong Xiangting
College of Materials Science and Engineering, Changchun University of Science and Technology, Changchun, 130022, China.
Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun, 130022, China.
Small. 2024 Apr;20(16):e2308603. doi: 10.1002/smll.202308603. Epub 2023 Nov 27.
The shuttle effect of lithium polysulfides (LiPSs) severely hinders the development and commercialization of lithium-sulfur batteries, and the design of high-conductive carbon fiber-host material has become a key solution to suppress the shuttle effect. In this work, a unique Co/CoN-carbon nanocages@TiO-carbon nanotubes structure (NC@TiO-CNTs) is constructed using an electrospinning and nitriding process. Lithium-sulfur batteries using NC@TiO-CNTs as cathode host materials exhibit high sulfur utilization (1527 mAh g at 0.2 C) and can still maintain a discharge capacity of 663 mAh g at a high current density of 5 C, and the capacity loss is only 0.056% per cycle during 500 cycles at 1 C. It is worth noting that even under extreme conditions (sulfur-loading = 90%, surface-loading = 5.0 mg cm , and E/S = 6.63 µL mg), the lithium-sulfur batteries can still provide a reversible capacity of 4 mAh cm. Throughdensity functional theory calculations, it has been found that the Co/CoN heterostructures can adsorb and catalyze LiPSs conversion effectively. Simultaneously, the TiO can adsorb LiPSs and transfer Li selectively, achieving dual confinement for the shuttle effect of LiPSs (nanocages and nanotubes). The new findings provide a new performance enhancement strategy for the commercialization of lithium-sulfur batteries.
多硫化锂（LiPSs）的穿梭效应严重阻碍了锂硫电池的发展和商业化，设计高导电性的碳纤维主体材料已成为抑制穿梭效应的关键解决方案。在这项工作中，通过静电纺丝和氮化工艺构建了一种独特的Co/CoN-碳纳米笼@TiO-碳纳米管结构（NC@TiO-CNTs）。以NC@TiO-CNTs作为正极主体材料的锂硫电池表现出高硫利用率（在0.2 C时为1527 mAh g），并且在5 C的高电流密度下仍可保持663 mAh g的放电容量，在1 C下500次循环期间容量损失仅为每循环0.056%。值得注意的是，即使在极端条件下（硫负载量 = 90%，表面负载量 = 5.0 mg cm，E/S = 6.63 μL mg），锂硫电池仍可提供4 mAh cm的可逆容量。通过密度泛函理论计算发现，Co/CoN异质结构可以有效吸附和催化LiPSs的转化。同时，TiO可以吸附LiPSs并选择性地转移Li，实现对LiPSs穿梭效应的双重限制（纳米笼和纳米管）。这些新发现为锂硫电池的商业化提供了一种新的性能增强策略。
