Hierarchical nitrogen-doped porous graphene/reduced fluorographene/sulfur hybrids for high-performance lithium-sulfur batteries
Hierarchical nitrogen-doped porous graphene/reduced fluorographene/sulfur hybrids for high-performance lithium-sulfur batteries
复制标题
用于高性能锂硫电池的分层氮掺杂多孔石墨烯/还原氟石墨烯/硫杂化物
DOI：
10.1039/c6cp07650e
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发表时间：
2017-01-21
影响因子：
3.3
通讯作者：
Chang, Haixin
中科院分区：
文献类型：
--
作者：
Liu, Zhixuan;Li, Jie;Chang, Haixin
在锂硫电池中，由于中间多硫化物的溶解，要获得高硫负载量和良好的循环性能的高性能正极是一个巨大的挑战。在这里，我们报道了一种新型的分级杂化材料，它由氮掺杂的多孔石墨烯(NG)、还原的荧烯或氟化石墨烯(RFG)和硫组成，作为锂-S电池的复合正极。与仅掺氮多孔石墨烯或纯还原荧烯的硫磺复合材料相比，由于多硫化物锂和硫磺的约束作用，分级混杂体系(NG-RFG/S)表现出更好的可逆容量和倍率性能。S含量接近63.2%的NG-RFG/S正极材料在0.1C循环100次后，放电容量达1120 mA h g(-1)，循环100次后仍保持632 mA h g(-1)。在0.5C的较高倍率下，电池在800次循环后仍保持约300 mA h g(-1)的放电容量，显示了这种混合阴极在长循环寿命、高能量密度存储应用中的巨大潜力。
It is a great challenge to obtain high performance cathodes with a high sulfur loading and good cycle performance due to the dissolution of intermediate lithium polysulfides in lithium-sulfur batteries. Herein, we report a novel hierarchical hybrid composed of nitrogen-doped porous graphene (NG), reduced fluorographene or graphene fluoride (RFG), and sulfur as a composite cathode in the Li-S batteries. In comparison with sulfur composites based on only either nitrogen-doped porous graphene or pure reduced fluorographene, the hierarchical hybrid of RFG, NG, and sulfur (NG-RFG/S) shows a better reversible capacity and rate capability performance due to a better confinement effect of lithium polysulfides and sulfur. The NG-RFG/S cathode with similar to 63.2% S content exhibits a high discharge capacity of 1120 mA h g(-1) and retains 632 mA h g(-1) after 100 cycles at 0.1C. At the higher rate of 0.5C, the cell still maintains a discharge capacity of about 300 mA h g(-1) after 800 cycles, which reveals the great potential of this hybrid cathode for long-cycle-life, high energy density storage applications.