Chang Zhi, Ding Bing, Dou Hui, Wang Jie, Xu Guiyin, Zhang Xiaogang
Jiangsu Key Laboratory of Material and Technology, for Energy Conversion, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P.R. China.
Chemistry. 2018 Mar 12;24(15):3768-3775. doi: 10.1002/chem.201704757. Epub 2018 Feb 19.
As one of the most promising energy storage devices, the practical application of lithium-sulfur batteries is limited by the low electrical conductivity of sulfur and the notable "shuttle effects" of sulfur-based electrodes. In this work, we describe a hierarchically porous N-doped zeolitic imidazolate framework-8 (ZIF-8)-derived carbon nanosphere (N-ZDC) with an outer shell and an inner honeycomb-like interconnected nanosheet network as sulfur host material for high-performance and long-term lithium-sulfur batteries. The N-ZDC serves as multilayered barrier against the dissolution of lithium polysulfides. The porously inner interconnected carbon network of the N-ZDC facilitates the electron and ion transportation, ensures a high sulfur loading, and accommodates a volume expansion of the sulfur species. As a result, the optimized N-ZDC /S electrodes displayed high initial specific capacities of 1343, 1182, and 698 mAh g at 0.5, 1, and 2 C, respectively, and an ultraslow capacity decay of only 0.048 % per cycle at 2 C over 800 cycles. Even with a high sulfur loading of 3.1 mg cm , N-ZDC /S still delivered a reversible capacity of 956 mAh g and stabilizes at 544 mAh g after 500 cycles at 0.5 C, revealing the great potential of the novel carbon nanospheres for energy storage application.
作为最具前景的储能装置之一，锂硫电池的实际应用受到硫的低电导率和硫基电极显著的“穿梭效应”的限制。在这项工作中，我们描述了一种具有外壳和内部蜂窝状互连纳米片网络的分级多孔氮掺杂沸石咪唑酯骨架-8（ZIF-8）衍生碳纳米球（N-ZDC），作为高性能和长寿命锂硫电池的硫主体材料。N-ZDC作为防止多硫化锂溶解的多层屏障。N-ZDC的多孔内部互连碳网络促进电子和离子传输，确保高硫负载，并适应硫物种的体积膨胀。结果，优化后的N-ZDC/S电极在0.5、1和2C时分别显示出1343、1182和698 mAh g的高初始比容量，在2C下800次循环中容量衰减仅为每循环0.048%。即使硫负载量高达3.1 mg cm，N-ZDC/S在0.5C下500次循环后仍具有956 mAh g的可逆容量，并稳定在544 mAh g，揭示了这种新型碳纳米球在储能应用中的巨大潜力。
