Shi Yang, Wang Shun, Cui Peiyu, Ma Jiacheng, Zhang Xingxing, Chen Zhuo, Hou Xuehan, Li Xiao, Jin Xilang, Zhang Yanan, Wang Yaoyu, Huang Wenhuan
Key Laboratory of Chemical Additives for China National Light Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Key Laboratory of Chemical Additives for China National Light Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Sci Bull (Beijing). 2025 Jul 15;70(13):2094-2103. doi: 10.1016/j.scib.2025.05.005. Epub 2025 May 8.
The widespread commercialization of lithium-sulfur (Li-S) batteries is hindered by two critical challenges: sluggish redox kinetics and the detrimental polysulfide shuttle effect. In this study, we present a novel approach utilizing hydrogen-bond-rich covalent organic frameworks (TTP@PVDF50), synthesized through an in situ self-assembly process incorporating polymeric guest species. These covalent organic frameworks (COFs), when integrated into the separators of Li-S batteries, preserve their intrinsic porosity and crystallinity, while the abundant fluorine-rich sites and well-defined pore structures enhance lithium-ion (Li) transport kinetics. The hydrogen-bond-rich nature of the COFs provides an effective strategy to mitigate the polysulfide shuttle, leveraging both spatial hindrance and strong polar interactions for enhanced adsorption. Density functional theory (DFT) calculations and in situ Raman spectroscopy reveal that the F∙∙∙OH hydrogen bonding network in the TTP@PVDF50 composite significantly accelerates Li migration and catalyzes the conversion of LiPSs. The modified separator demonstrates a high discharge capacity of 1420.2 mAh g at 0.2 C (1 C=1675 mAh g), alongside remarkable anti-self-discharge performance with only 9.0% capacity loss. Notably, the Li-S battery with a high sulfur loading (4.59 mg cm) and a lean electrolyte (6 µL mg) retains over 83% of its capacity, underscoring the effectiveness of this strategy in advancing the performance and longevity of Li-S batteries.
锂硫（Li-S）电池的广泛商业化受到两个关键挑战的阻碍：氧化还原动力学缓慢和有害的多硫化物穿梭效应。在本研究中，我们提出了一种新颖的方法，利用富含氢键的共价有机框架（TTP@PVDF50），通过结合聚合物客体物种的原位自组装过程合成。这些共价有机框架（COF）集成到Li-S电池的隔膜中时，保留了其固有孔隙率和结晶度，同时丰富的富氟位点和明确的孔结构增强了锂离子（Li）传输动力学。COF富含氢键的性质提供了一种有效的策略来减轻多硫化物穿梭，利用空间位阻和强极性相互作用来增强吸附。密度泛函理论（DFT）计算和原位拉曼光谱表明，TTP@PVDF50复合材料中的F∙∙∙OH氢键网络显著加速Li迁移并催化多硫化锂（LiPSs）的转化。改性隔膜在0.2 C（1 C = 1675 mAh g）下表现出1420.2 mAh g的高放电容量，同时具有仅9.0%容量损失的显著抗自放电性能。值得注意的是，具有高硫负载（4.59 mg cm）和贫电解质（6 µL mg）的Li-S电池保留了超过83%的容量，突出了该策略在提高Li-S电池性能和寿命方面的有效性。
